Human tissue factor related DNA segments

ABSTRACT

DNA segments include DNA sequences defining a structural gene coding for a human tissue factor heavy chain protein and a precursor form of that protein are disclosed. Recombinant DNA molecules capable of expressing a human tissue factor heavy chain protein are also disclosed. Further disclosed are human tissue factor heavy chain binding site polypeptide analogs as well as methods for their use.

This invention was made with the support of the United StatesGovernment, and the United States Government has certain rights in theinvention pursuant to National Institutes of Health Contracts P01HL16411, T32 AIO7244 and P01 CA41085.

CROSS REFERENCE TO RELATED APPLICATION

This is a continuation-in-part application of Ser. No. 033,047, filedMar. 31, 1987, now abandoned.

TECHNICAL FIELD

The present invention relates to a recombinant DNA molecule carrying astructural gene that encodes the human tissue factor heavy chain protein(huTFh). More specifically, this invention relates to an expressionvector capable of expressing huTFh in host cells containing that vector.The present invention also relates to a synthetic polypeptide analog ofhuTFh and monoclonal antibodies that bind huTFh and the polypeptideanalogs.

BACKGROUND OF THE INVENTION

The clotting of blood involves a serial cascade of enzyme, cofactor,proteolytic and gelation reactions mediated by a group of cellular andplasma proteins known as coagulation factors. Initiation of this cascadecan occur when the cellular receptor known as tissue factor (TF) bindscoagulation factor VII or its derivative, factor VIIa, to form acatalytically active complex. In the absence of TF and without continuedbinding in a complex, factor VII/VIIa does not initiate coagulation.Thus, the chemical and biological characterization of TF is clearlyimportant to understanding the mechanism of coagulation.

Tissue factor is a membrane-bound glycoprotein that is not normallyfound soluble in the circulation or accessible to plasma proteinsincluding factor VII/VIIa and the other coagulation factors. Whiletissue factor is not normally expressed on the surface of cells thatform the vasculature, its expression by monocytes within the vasculaturecan be induced by infectious agent constituents such as bacteriallipopolysaccharides, lymphokines derived from some antigen-stimulated Thelper cells, directly by some stimulated T helper cells, and immunecomplexes. Certain inflammatory mediators of monocyte/macrophage origin,e.g. interlukin 1 and tumor necrosis factor alpha as well as bacteriallipopolysaccharide, can stimulate endothelial cells that line thehumoral surface of blood vessels to express TF. Expression of TF in thevascular compartment typically results in disseminated intravascularcoagulation or localized initiation of clotting, i.e., thrombogenesis.

Tissue factor is constitutively expressed on the surface of someextravascular cells in in vitro culture including fibroblasts, some asyet unidentified types of brain cells, and certain epithelia that areseparated from the circulating plasma proteins by basement membranebarriers. The presence of TF on these cells results in clot formationupon contact with blood as a result of tissue damage. Thus, TF is thefoundation upon which the hemostatic system is initiated.

The report of Howell, Am. J. Physiol, 31:1 (1912) was the first tosuggest that an isolated tissue protein preparation containing TF couldpromote coagulation only when present as a phospholipidproteinlipoprotein) complex. Reconstituting the functional procoagulantactivity of TF by relipidating the isolated protein has been necessarybecause isolation of the TF-containing tissue protein typically resultsin removal of the phospholipids which are normally associated with theTF protein, such reconstitution has been studied by a number ofinvestigators. For instance, recovery of coagulant activity has beenreported to be influenced by the phospholipid type, the ratio ofphospholipid to protein, and the detergent and ionic composition of thereconstitution mixture. See Nemerson, J. Clin. Invest., 47-72 (1968);Nemerson, J. Clin. Invest., 48-322 (1969); and Carson et al., Science,208:307 (1980).

Both isolated and relipidated TF-containing protein preparations havebeen prepared by extraction from the tissues of various species.Historically, the methods used were difficult, time consuming andresulted in low yields because tissue factor is only present inextremely small quantities in naturally occurring tissues. For a reviewof the classical methods, see Nemerson et al., Prog. Hem. Thromb.,237-261 (1982).

More recently, Broze et al., J. Biol. Chem., 60:10917-20 (1985), Bom etal., Thromb. Res., 42:635-643 (1986) and Guha et al., Proc. Natl. Acad.Sci, U.S.A., 83:299-302 (1986) have reported isolating human tissuefactor (huTF) protein using a method based on the discovery thatdelipidated tissue factor protein can bind factor VII/VIIa when theprotein is solubilized in an aqueous solution containing a non-ionicdetergent and CaCl₂. However, the utility of that method, which employsa factor VII/VIIa affinity sorbent, as a means for isolating tissuefactor protein is limited not only by the difficulty in obtainingsignificant quantities of isolated factor VII/VIIa but also by thelability of factor VII/VIIa.

Broze et al., supra, have suggested that the development of monoclonalantibodies specific for huTF and their use as immunoaffinity sorbentscould circumvent problems caused by the limited availability of factorVII/VIIa. However, no anti-huTF monoclonal antibodies have been reportedin the literature. Furthermore, two monoclonal antibodies raised againstbovine TF [Carson et al., Blood, 662-156 (1985)] do not immunoreact withhuTF (Guha et al., supra).

BRIEF SUMMARY OF THE INVENTION

In one embodiment, the present invention contemplates DNA segmentcomprising no more than about 12,000 nucleotide base pairs including asequence defining a structural gene coding for a human tissue factorheavy chain (huTFh) protein. Preferably the structural gene codes for aprotein having an amino acid residue sequence represented by FIG. 1 fromabout residue 1 to about residue 263. More preferably, the structuralgene has a nucleotide base sequence represented by FIG. 2 from aboutbase 130 to about base 918.

In preferred embodiments, the DNA segment also includes a secondsequence contiguous with the 5' terminus of the first sequence andcoding for an amino acid residue leader sequence attached to theamino-terminus of the huTFh protein. The first and second DNA sequencestogether define a composite structural gene coding for a human tissuefactor heavy chain precursor (pre-huTFh) protein. Preferably thecomposite structural gene codes for a protein having an amino acidresidue sequence represented by FIG. 1 about residue -32 to aboutresidue 263. More preferably the composite structural gene has anucleotide base sequence represented by FIG. 2 from about base 34 toabout base 918.

In another embodiment, the present invention contemplates recombinantDNA molecule comprising a vector operatively linked to a first DNAsegment that defines a structural gene coding for a human tissue factorheavy chain protein. Preferably, the recombinant DNA molecule furtherincludes a second DNA segment contiguous with the 5' terminus of firstsegment and coding for an amino acid residue leader sequence attached tosaid protein; said first and second DNA segments together defining acomposite structural gene that codes for a precursor form of saidprotein.

In another embodiment, the present invention contemplates human tissuefactor binding site polypeptide analog comprising no more than about 50amino acid residues and including an amino acid residue sequence thatcorresponds to a sequence represented by the formula:

    --VNQVYT--.

More preferably, the present invention contemplates human tissue factorbinding site polypeptide analog comprising no more than about 50 aminoacid residues and including an amino acid residue sequence thatcorresponds to a sequence represented by a formula selected from thegroup consisting of:

    --VNQVYTVQIST--,

and

    --LYYWKSSSSGKKT--.

A further embodiment of the present invention is an antibody compositioncomprising antibody molecules that:

a) immunoreact with human tissue factor heavy chain protein;

b) immunoreact with a polypeptide represented by a formula selected fromthe group consisting of:

H-EWEPKPVNQVYT-OH,

H-EPKPVNQVYTVQISTKSGDWKSKC-OH,

H-VFGKDLIYTLYYWKSSSSGKKT-OH,

H-IYTLYYWKSSSSGKKTAK-OH,

H-SSSGKKTAKTNTNEFLIDVDKGENYCFSV-OH,

H-SGTTNTVAAYNLTWKSTNFKTILEWEPKPV-OH,

H-TKSGDWKSKCFYTTDTECDLTDEIVKDVKQTY-OH,

H-KSGDWKSKC-OH,

H-ECDLTDEIVKDVKQTY-OH,

H-LARVFSYPAGNVESTGSAGEPLYENSPEFTPYLC-OH,

H-YENSPEFTPYLETNLGQPTIQSFEQVGTKV-OH, and

H-QAVIPSRTVNRKSTDSPVEC-OH; and

c) do not substantially immunoreact with a polypeptide represented bythe formula shown in FIG. 1 from position 204 to position 226.

Also contemplated by the present invention are the hybridomas TF8-5G9,TF9-10H10 and TF9-6B4, as well as monoclonal antibody compositionscomprising antibody molecules produced by those hybridomas.

The present invention also contemplates a method of assaying for thepresence of human tissue factor heavy chain protein in a body fluidsample comprising the steps of:

a) admixing a body sample with antibodies that immunoreact with humantissue factor heavy chain protein to form an immunoreaction admixture;

b) maintaining the admixture for a time period sufficient for theantibodies to immunoreact with any human tissue factor present in thesample and form an immunoreaction product; and

c) detecting the presence of any immunoreaction product formed in stepb.

Also contemplated is a method of detecting a thrombus in vivo comprisingthe steps of:

a) intravenously administering to a human subject a monoclonal antibodycomposition comprising a physiologically tolerable diluent and an amountof antibody molecules produced by hybridoma TF9-10H10 linked to an invivo indicating means effective to immunoreact with human tissue factorpresent in a thrombus;

b) maintaining the administered subject for a predetermined time periodsufficient for the antibody molecules to immunoreact with tissue factorpresent in vivo as part of a thrombus and form an immunoreactionproduct; and

c) assaying for the presence of any immunoreaction product formed instep (b).

Further contemplated is a method of neutralizing the ability of humantissue factor to bind coagulation factor VII/VIIa in vivo comprisingintravenously administering to a human subject a monoclonal antibodycomposition comprising a physiologically tolerable diluent containing anamount of antibody molecules produced by a hybridoma selected from thegroup consisting of: TF8-5G9 and TF9-6B4 effective to bind to humantissue factor present.

The present invention also contemplates a method of inhibiting thebinding of human tissue factor to coagulation factor VII/VIIa in vivocomprising intravenously administering to a human subject a polypeptidecomposition comprising a physiologically tolerable diluent containing apolypeptide selected from the group consisting of:

H-EWEPKPVNQVYT-OH,

H-EPKPVNQVYTVQISTKSGDWKSKC-OH,

H-VFGKDLIYTLYYWKSSSSGKKT-OH,

H-IYTLYYWKSSSSGKKTAK-OH, and

H-SSSGKKTAKTNTNEFLIDVDKGENYCFSV-OH;

said polypeptide present in said composition in an amount effective toreact with factor VII/VIIa.

In another embodiment the present invention contemplates a diagnosticsystem in kit form for assaying for the presence of human tissue factorheavy chain protein in sample comprising a package containing anantibody composition of this invention. Preferably, the antibodycomposition comprises monoclonal antibody molecules produced by ahybridoma selected from the group of hybridomas consisting of:

a) TF8-5G9,

b) TF9-6B4, and

c) TF9-10H10.

A method of isolating blood coagulation factor VII/VIIa from a sample isalso contemplated. The method comprises the steps of:

a) admixing the sample with a solid support comprising a polypeptide ofclaim 15 affixed to a solid matrix, said admixing forming a bindingreaction admixture;

b) maintaining said binding reaction admixture for a time periodsufficient for said coagulation factor to bind to said polypeptide andform a solid phase complex and a supernatant;

c) separating said supernatant from said complex; and

d) recovering said coagulation factor from the separated complex of stepC.

Further contemplated is a composition comprising an aqueous solution ofbiologically active human tissue factor heavy chain proteinsubstantially free of human tissue factor light chain protein.Preferably the biologically active human tissue factor heavy chainprotein is dispersed in a phospholipid or a non-ionic detergent.

A diagnostic system in kit form for assaying for coagulation competencein a vascular system fluid sample is also contemplated It includes apackage containing a composition an aqueous solution of biologicallyactive human tissue factor heavy chain protein substantially free ofhuman tissue factor light chains protein wherein said heavy chainprotein is present in an amount sufficient to perform at least oneassay. Preferably, the heavy chain protein is dispersed in aphospholipid.

In another embodiment a method of preparing mature human tissue factorheavy chain protein and the protein expression product of that methodare contemplated. The method includes the steps of:

a) initiating a culture, in a nutrient medium, of mammalian cellstransformed with a recombinant DNA molecule comprising an expressionvector compatible with said cells operatively linked to a first DNAsegment that defines a structural gene coding for a human tissue factorheavy chain protein and a second DNA segment contiguous with said firstsegment and coding for an amino acid residue leader sequence attached tosaid protein; said first and second DNA segments together defining acomposite structural gene that codes for a precursor form of saidprotein;

b) maintaining said culture for a time period sufficient for said cellsto express protein from said recombinant DNA molecule and form saidmature protein; and

c) recovering said mature protein from said culture.

BRIEF SUMMARY OF THE DRAWINGS

In the drawings forming a portion of this disclosure:

FIG. 1 illustrates the complete amino acid residue sequence of themature and precursor forms of human tissue factor heavy chain proteins(huTFh and pre-huTFh, respectively), shown from left to right and in thedirection from amino-terminus to carboxy-terminus using the singleletter amino acid residue code. The amino acid residue sequence of thepredominant naturally occurring mature protein form is numbered 1 to263. The sequence of the lesser found mature form begins at amino acidresidue number 3 and ends at residue 263.

The amino acid residue sequence corresponding to the leader sequence(precursor portion) of the pre-huTFh protein that is removed during thematuration process is designated by negative numbers. The extracellulardomain and transmembrane anchor region correspond to residue positions 1to 219 and 220 to 242, respectively.

FIG. 2 illustrates the nucleotide sequence of a cDNA that codes for thepre-huTFh and huTFh proteins, shown from left to right and in thedirection of 5' terminus to 3' terminus using the single letternucleotide base code. The structural gene for huTFh begins at base 130and ends at base 918.

The reading frame is indicated by placement of the deduced amino acidresidue sequence above the nucleotide sequence such that the singleletter that represents each amino acid residue is located above themiddle base in the corresponding codon.

FIG. 3 is a graph illustrating the coagulation assay used to measurehuTF procoagulant activity as described in Example 2. A log-log plot isshown of human citrated plasma coagulation (clotting) time in secondsversus the human tissue factor (huTF) concentration in picograms permilliliter (pg/ml).

FIG. 4 illustrates an autofluorogram of factor VII/VIIaaffinity-isolated huTF electrophoresed in a 10% polyacrylamide gel. LaneA shows ¹²⁵ I-labeled huTF that was isolated and reduced withdithiothreitol (DTT) prior to electrophoresis as described in Example 4.Lane B shows molecule-weight standards with apparent molecular weightsindicated in kilodaltons (k).

FIG. 5 illustrates an autofluorogram of factor VII/VIIaaffinity-isolated huTF electrophoresed in 15% polyacrylamide gels.Isolation, labeling with ¹²⁵ I and electrophoresis of huTF were done asdescribed in Example 4. Lane A shows the isolated huTF after reductionwith DTT. Lane B shows the same sample electrophoresed without reductionwith DTT. The upper and lower bands (labeled U and L) correspond to theapproximately 58 and 47 k size forms of huTF. After autofluorography,the upper and lower bands were excised, rehydrated in SDS sample buffercontaining DTT, inserted into the sample well of a second 15%polyacrylamide gel and subjected to electrophoresis. Lane C shows there-electrophoresis of the lower band obtained from Lane B. Lane D showsthe reelectrophoresis of the upper band obtained from Lane B. The 12.5and 47 kilodalton (k) apparent molecular weight proteins are indicatedby the arrows.

FIG. 6 illustrates an autofluorogram of factor VII/VIIaaffinity-isolated huTF that was first immunoprecipitated with thehuTF-specific monoclonal antibody TF8-5G9 and then electrophoresed in a8 to 17% polyacrylamide gradient gel as described in Example 4. Lane Ashows ¹²⁵ I-labeled huTF electrophoresed with reduction by DTT. Lane Bshows the same sample electrophoresed without reduction.

FIG. 7 illustrates an autofluorogram of factor VII/VIIaaffinity-isolated huTF electrophoresed in 15% polyacrylamide gels.Isolation, labeling with ¹²⁵ I, reduction and deglycosylation wereconducted as described in Example 4. Lane 1 contains the followingprotein standards electrophoresed as markers with apparent molecularweights (Mr) indicated in kilodaltons; lysozyme, 14.3; carbonicanhydrase, 30.0; ovalbumin, 46.0; bovine serum albumin, 69.0;phosphorylase b, 92.5; and myosin, 200.0, all obtained from Amersham,Arlington Heights, Ill. ¹²⁵ I-huTF-containing samples wereelectrophoresed either with DTT (Lanes 2 and 3) or without DTT (Lanes 4and 5). Some of these ¹²⁵ I-huTF-containing samples were deglycosylated(Lanes 3 and 5) while others were not deglycosylated (Lanes 2 and 4)before electrophoresis.

The ¹²⁵ I-huTF-containing samples run in Lanes 3 and 5 weredeglycosylated prior to electrophoresis while those in Lanes 2 and 4were not.

FIG. 8 illustrates an autofluororgram of immunoaffinity-isolated huTFelectrophoresed in 10% polyacrylamide gels as described in Example 9.Lane 1 contains the following protein standards electrophoresed asmarkers with apparent molecular weights (Mr) indicated in kilodaltons;cytochrome c, 12.4; lactoglobulin, 18.4; carbonic anhydrase, 29.0;lactate dehydrogenase, 36.0; ovalbumin, 43.0; glutamate dehydrogenase,55.0; and phosphorylase b, 95.5, all obtained from Diversified Biotech(Newton Centre, Mass.).

Lane 2 contains about 20 ug of protein, determined using the BCA proteinassay method of Smith et al., Anal. Bioch., 150:76-85 (1985), andreduced using DTT. huTF heavy chain (huTFh) is clearly visible atapproximately 47 Mr and huTF light chain is faintly visible atapproximately 12.5 Mr. Protein was visualized by Coomassie blue stainingas described by Laemmli, Nature, 227:680-685 (1970).

FIG. 9 is a graph illustrating the dose-response curve of inhibition ofhuTF-initiated coagulation by non-phospholipidated (non-lipidated)polypeptide analogs of huTFh. Percent inhibition of coagulation byvarious concentrations of non-lipidated polypeptides was measured asdescribed in Example 12. Polypeptides tested include p26-49 (Δ,TF26.49),p121-155 (◯, TF121.155), p146-167 ( , TF146.167) and p204-226 (,TF204.226).

FIG. 10 is a graph illustrating the dose-response curve of inhibition ofhuTF-initiated coagulation by phospholipidated (lipidated) polypeptideanalogs of huTFh. Percent inhibitions were measured by the same methodsand for the same analogs as described in FIG. 9.

FIG. 11 illustrates the restriction maps of the EcoRI segment insertswithin the recombinant DNA plasmids pCTF64, pCTF314 and pCTF403. Theinserts ( ) represent overlapping portions of nucleotide sequences thattogether correspond to the complete nucleotide sequence of the pre-huTFhgene. Individually, the inserts include nucleotide residues thatcorrespond from left to right and in the direction of 5' to 3' to thenucleotide sequence shown in FIG. 2 from base residues 1-486 (containedin pCTF64), residues 135-775 (contained in pCTF314) and residues776-1125 (contained in pCTF403). Also shown is the approximate locationof restriction endonuclease cleavage sites within the inserts that wereused in constructing the various recombinant DNA molecules described inExample 16. Further indicated is the approximate location of thecorresponding pre-huTFh protein with its leader peptide ( ) andtransmembrane anchor domain ( ) shown intact.

FIG. 12 is a graph illustrating the dose-response curve of inhibition ofhuTF-initiated coagulation by non-phospholipidated (non-lipidated)polypeptide analogs of huTFh. Percent inhibition (%) of coagulation byvarious concentrations expressed in molarity (M) of non-lipidatedpolypeptides was measured as described in Example 12. Polypeptidesexamined include p24-35 (Δ), p26-49 (O), p152-169 (□) and the peptides,p40-71, p72-104, p94-123 and p161-189 which all produced no substantialinhibition and are collectively indicated by the closed circle ( ).

FIG. 13 is a graph illustrating the kinetics of inhibition ofcoagulation by a TF8-5G9 antibody composition. Percent inhibition (%) ofcoagulation is plotted over various antibody immunoreaction timesmeasured as described in Example 18.

FIG. 14 is a graph illustrating the dose response of inhibition ofhuTF-initiated coagulation by anti-huTF antibodies. Percent (%)inhibition of coagulation by various concentrations of the anti-huTFmonoclonal antibody TF8-5G9 was measured as described in Example 19.

FIG. 15 is a graph illustrating the dose-response of inhibition ofhuTF-initiated coagulation by anti-huTF antibodies where the source ofhuTF is a human cell lysate of the fibroblast cell line GM1381. Percentinhibition (%) of coagulation by various concentrations of the anti-huTFmonoclonal antibody TF8-5G9 was measured as described in Example 19.Open circles (O) designate TF8-5G9 antibody and closed circles ( )designate an irrelevant antibody.

DETAILED DESCRIPTION OF THE INVENTION A. Definitions

Amino Acid: All amino acid residues identified herein are in the naturalL-configuration. In keeping with standard polypeptide nomenclature, J.Biol. Chem., 243:3557-59, (1969), abbreviations for amino acid residuesare as shown in the following Table of Correspondence:

    ______________________________________                                        TABLE OF CORRESPONDENCE                                                       SYMBOL                                                                        1-Letter  3-Letter        AMINO ACID                                          ______________________________________                                        Y         Tyr             L-tyrosine                                          G         Gly             glycine                                             F         Phe             L-phenylalanine                                     M         Met             L-methionine                                        A         Ala             L-alanine                                           S         Ser             L-serine                                            L         Ile             L-isoleucine                                        L         Leu             L-leucine                                           T         Thr             L-threonine                                         V         Val             L-valine                                            P         Pro             L-proline                                           K         Lys             L-lysine                                            H         His             L-histidine                                         Q         Gln             L-glutamine                                         E         Glu             L-glutamic acid                                     W         Try             L-tryptophan                                        R         Arg             L-arginine                                          D         Asp             L-aspartic acid                                     N         Asn             L-asparagine                                        C         Cys             L-cysteine                                          ______________________________________                                    

It should be noted that all amino acid residue sequences are representedherein by formulae whose left to right orientation is in theconventional direction of amino-terminus to carboxy-terminus.Furthermore, it should be noted that a dash at the beginning or end ofan amino acid residue sequence indicates a bond to a radical such as Hand OH (hydrogen and hydroxyl) at the amino- and carboxy-termini,respectively, or a further sequence of one or more amino acid residuesup to a total of about fifty residues in the polypeptide chain.

Polypeptide and Peptide: Polypeptide and peptide are terms usedinterchangeably herein to designate a linear series of no more thanabout 50 amino acid residues connected one to the other by peptide bondsbetween the alpha-amino and carboxy groups of adjacent residues.

Protein: Protein is a term used herein to designate a linear series ofgreater than 50 amino acid residues connected one to the other as in apolypeptide.

Nucleotide: a monomeric unit of DNA or RNA consisting of a sugar moiety(pentose), a phosphate, and a nitrogenous heterocyclic base. The base islinked to the sugar moiety via the glycosidic carbon (1' carbon of thepentose) and that combination of base and sugar is a nucleoside. Whenthe nucleoside contains a phosphate group bonded to the 3' or 5'position of the pentose it is referred to as a nucleotide.

Base Pair (bp): A partnership of adenine (A) with thymine (T), or ofcytosine (C) with guanine (G) in a double stranded DNA molecule.

B. DNA Segments

In living organisms, the amino acid residue sequence of a protein orpolypeptide is directly related via the genetic code to thedeoxyribonucleic acid (DNA) sequence of the structural gene that codesfor the protein. Thus, a structural gene can be defined in terms of theamino acid residue sequence, i.e., protein or polypeptide, for which itcodes.

An important and well known feature of the genetic code is itsredundancy. That is, for most of the amino acids used to make proteins,more than one coding nucleotide triplet (codon) can code for ordesignate a particular amino acid residue. Therefore, a number ofdifferent nucleotide sequences may code for a particular amino acidresidue sequence. Such nucleotide sequences are considered functionallyequivalent since they can result in the production of the same aminoacid residue sequence in all organisms. Occasionally, a methylatedvariant of a purine or pyrimidine may be incorporated into a givennucleotide sequence. However, such methylations do not affect the codingrelationship in any way.

The DNA segments of the present invention are characterized as includinga DNA sequence that encodes a human tissue factor heavy chain protein(huTFh). In preferred embodiments the DNA segment includes a DNAsequence that encodes a human tissue factor heavy chain precursorprotein (pre-huTFh). That is, the DNA segments of the present inventionare characterized by the presence of a huTFh or, more preferably, apre-huTFh, structural gene. Further preferred are DNA segments thatinclude a DNA sequence forming a structural gene encoding a solublehuTFh or soluble pre-huTFh protein. Preferably the gene is present as anuninterrupted linear series of codons where each codon codes for anamino acid residue found in the huTFh or pre-huTFh protein, i.e., a genefree of introns.

Thus, a DNA segment consisting essentially of the sequence shown in FIG.2 from about position 130 at its 5' terminus to about position 918 atits 3' terminus, and capable of expressing huTFh constitutes oneembodiment of the present invention. A DNA segment consistingessentially of the sequence shown in FIG. 2 from about position 34 toabout position 918 and capable of expressing pre-huTFh constitutesanother embodiment of the invention.

A preferred soluble huTFh molecule lacks the amino acid residues encodedby the last about one hundred-fifty bases at the 5' terminus of the DNAthat codes for huTFh. Thus, a DNA segment consisting essentially of thesequence shown in FIG. 2 from about position 130 at its 5' terminus toabout position 756 through about position 801 at its 3' terminus, andcapable of expressing soluble huTFh constitutes a further preferredembodiment of this invention. Exemplary preferred DNA segments formingsoluble huTFh structural genes are those having a nucleotide basesequence represented by FIG. 2 from about base 130 to about base 756,from about base 130 to about base 771, from about base 130 to about base786, and from about base 130 to about base 801.

Preferred DNA segments encoding a soluble pre-huTFh are similar to thoseencoding soluble huTFh except that they encode proteins containing anamino terminal leader sequence such as amino acid residues -32 to 0 asshown in FIG. 1. Thus, a preferred DNA segment forming a structural geneencoding soluble pre-huTFh consists essentially of the sequence shown inFIG. 2 from about position 34 at its 5' terminus to about position 756through about position 801 at its 3' terminus. Exemplary preferredsoluble pre-huTFh-encoding DNA segments are those having a nucleotidebase sequence represented by FIG. 2 from about basse 34 to about base756, from about base 34 to about base 771, from about base 34 to aboutbase 786, and from about base 34 to about base 801.

Homologous DNA and RNA sequences that encode the above huTFh andpre-huTFh proteins, including their soluble forms, are alsocontemplated, as discussed before.

DNA segments that encode huTFh and pre-huTFh proteins can easily besynthesized by chemical techniques, for example, the phosphotriestermethod of Matteucci et al., J. Am. Chem. Soc., 103:3185 (1981). Ofcourse, by chemically synthesizing the coding sequence, any desiredmodifications can be made simply by substituting the appropriate basesfor those encoding the native amino acid residue sequence. However, DNAmolecules including sequences exactly homologous to those shown in FIG.2 are preferred.

Furthermore, DNA segments consisting essentially of structural genesencoding the huTFh and pre-huTFh proteins can be obtained fromrecombinant DNA molecules containing those genes. For instance, theplasmid type recombinant DNA molecules pCTF64, pCTF314 and pCTF403 eachcontain DNA sequences encoding different portions of the huTFh andpre-huTFh proteins and together possess the entire sequence of DNAnecessary for expression of either protein. Cultures of Escherichia coli(E. coli) transformed with either pCTF64, pCTF314 or pCTF403 have beendeposited pursuant to Budapest Treaty requirements with the AmericanType Culture Collection, (ATCC) 12301 Parklawn Drive, Rockville, Md.20852 on Mar. 27, 1987 and were assigned the following respectiveaccession numbers 67370, 67368 and 67369.

A DNA segment that includes a DNA sequence encoding huTFh or pre-huTFhcan be prepared by operatively linking (ligating) appropriaterestriction fragments from each of the above deposited plasmids usingwell known methods. The DNA molecules of the present invention producedin this manner typically have cohesive termini, i.e., "overhanging"single-stranded portions that extend beyond the double-stranded portionof the molecule. The presence of cohesive termini on the DNA moleculesof the present invention is preferred.

Also contemplated by the present invention are ribonucleic acid (RNA)equivalents of the above described DNA segments.

C. Recombinant DNA Molecules

The recombinant DNA molecules of the present invention can be producedby operatively linking a vector to a DNA segment of the presentinvention.

As used herein, the term "vector" refers to a DNA molecule capable ofautonomous replication in a cell and to which another DNA segment can beoperatively linked so as to bring about replication of the attachedsegment. Vectors capable of directing the expression of HuTFh andpre-huTFh genes are referred to herein as "expression vectors". Thus, arecombinant DNA molecule (rDNA) is a hybrid DNA molecule comprising atleast two nucleotide sequences not normally found together in nature.

The choice of vector to which a DNA segment of the present invention isoperatively linked depends directly, as is well known in the art, on thefunctional properties desired, e.g., protein expression, and the hostcell to be transformed, these being limitations inherent in the art ofconstructing recombinant DNA molecules. However, a vector contemplatedby the present invention is at least capable of directing thereplication, and preferably also expression, of the huTFh or pre-huTFhstructural genes included in DNA segments to which it is operativelylinked.

In preferred embodiments, a vector contemplated by the present inventionincludes a procaryotic replicon, i.e., a DNA sequence having the abilityto direct autonomous replication and maintenance of the recombinant DNAmolecule extrachromosomally in a procaryotic host cell, such as abacterial host cell, transformed therewith. Such replicons are wellknown in the art. In addition, those embodiments that include aprocaryotic replicon also include a gene whose expression confers drugresistance to a bacterial host transformed therewith. Typical bacterialdrug resistance genes are those that confer resistance to ampicillin ortetracycline.

Those vectors that include a procaryotic replicon can also include aprocaryotic promoter capable of directing the expression (transcriptionand translation) of the huTFh genes in a bacterial host cell, such as E.coli, transformed therewith. A promoter is an expression control elementformed by a DNA sequence that permits binding of RNA polymerase andtranscription to occur. Promoter sequences compatible with bacterialhosts are typically provided in plasmid vectors containing convenientrestriction sites for insertion of a DNA segment of the presentinvention. Typical of such vector plasmids are pUC8, pUC9, pBR322 andpBR329 available from Biorad Laboratories, (Richmond, Calif.) and pPLand pKK223 available from Pharmacia, Piscataway, N.J.

Expression vectors compatible with eucaryotic cells, preferably thosecompatible with vertebrate cells, can also be used to form therecombinant DNA molecules of the present invention. Eucaryotic cellexpression vectors are well known in the art and are available fromseveral commercial sources. Typically, such vectors are providedcontaining convenient restriction sites for insertion of the desired DNAsegment. Typical of such vectors are pSVL and pKSV-10 (Pharmacia),pBPV-1/pML2d (International Biotechnologies, Inc.), and pTDT1 (ATCC,#31255).

In preferred embodiments, the eucaryotic cell expression vectors used toconstruct the recombinant DNA molecules of the present invention includea selection marker that is effective in an eucaryotic cell, preferably adrug resistance selection marker. A preferred drug resistance marker isthe gene whose expression results in neomycin resistance, i.e., theneomycin phosphotransferase (neo) gene. Southern et al., J. Mol. Appl.Genet., 1:327-341 (1982).

The use of retroviral expression vectors to form the rDNAs of thepresent invention is also contemplated. As used herein, the term"retroviral expression vector" refers to a DNA molecule that includes apromoter sequence derived from the long terminal repeat (LTR) region ofa retrovirus genome.

In preferred embodiments, the expression vector is typically aretroviral expression vector that is preferably replication-incompetentin eucaryotic cells. The construction and use of retroviral vectors hasbeen described by Sorge et al., Mol. Cell. Biol., 4:1730-37 (1984).

A variety of methods have been developed to operatively link DNA tovectors via complementary cohesive termini. For instance, complementaryhomopolymer tracts can be added to the DNA segment to be inserted and tothe vector DNA. The vector and DNA segment are then joined by hydrogenbonding between the complementary homopolymeric tails to formrecombinant DNA molecules.

Synthetic linkers containing one or more restriction sites provide analternative method of joining the DNA segment to vectors. The DNAsegment, generated by endonuclease restriction digestion as describedearlier, is treated with bacteriophage T4 DNA polymerase or E. coli DNApolymerase I, enzymes that remove protruding, 3', single-strandedtermini with their 3'-5' exonucleolytic activities and fill in recessed3' ends with their polymerizing activities. The combination of theseactivities therefore generates blunt-ended DNA segments. The blunt-endedsegments are then incubated with a large molar excess of linkermolecules in the presence of an enzyme that is able to catalyze theligation of blunt-ended DNA molecules, such as bacteriophase T4 DNAligase. Thus, the products of the reaction are DNA segments carryingpolymeric linker sequences at their ends. These DNA segments are thencleaved with the appropriate restriction enzyme and ligated to anexpression vector that has been cleaved with an enzyme that producestermini compatible with those of the DNA segment.

Synthetic linkers containing a variety of restriction endonuclease sitesare commercially available from a number of sources includingInternational Biotechnologies, Inc., New Haven, Conn.

Also contemplated by the present invention are RNA equivalents of theabove described recombinant DNA molecules.

D. Transformed Cells and Cultures

The present invention also relates to a host cell transformed with arecombinant DNA molecule of the present invention preferably an rDNAcapable of expressing a soluble form of huTFh or pre-huTFh. The hostcell can be either procaryotic or eucaryotic. Bacterial cells arepreferred procaryotic host cells and typically are a strain of E. colisuch as, for example the E. coli strain DH5 available from BethesdaResearch Laboratories, Inc., Bethesda, Md. Preferred eucaryotic hostcells include yeast and mammalian cells, preferably vertebrate cellssuch as those from a mouse, rat, monkey or human fibroblastic cell line.Preferred eucaryotic host cells include Chinese hamster ovary (CHO)cells available from the ATCC as CCL61 and NIH Swiss mouse embryo cellsNIH/3T3 available from the ATCC as CRL 1658. Transformation ofappropriate cell hosts with a recombinant DNA molecule of the presentinvention is accomplished by well known methods that typically depend onthe type of vector used. With regard to transformation of procaryotichost cells, see, for example, Cohen et al., Proc. Natl. Acad. Sci.U.S.A., 69:2110 (1972); and Maniatis et al., Molecular Cloning, ALaboratory Mammal, Cold Spring Harbor Laboratory, Cold Spring Harbor,N.Y. (1982). With regard to transformation of vertebrate cells withretroviral vectors containing rDNAs, see, for example, Sorge et al.,Mol. Cell. Biol., 4:1730-37 (1984); Graham et al., Virol., 52:456(1973); and Wigler et al., Proc. Natl. Acad. Sci. U.S.A., 76:1373-76(1979).

Successfully transformed cells, i.e., cells that contain a recombinantDNA molecule of the present invention, can be identified by well knowntechniques. For example, cells resulting from the introduction of anrDNA of the present invention can be cloned to produce monoclonalcolonies. Cells from those colonies can be harvested, lysed and theirDNA content examined for the presence of the rDNA using a method such asthat described by Southern, J. Mol. Biol., 98:503 (1975) or Berent etal., Biotech., 3:208 (1985).

In addition to directly assaying for the presence of rDNA, successfultransformation can be confirmed by well known immunological methods whenthe rDNA is capable of directing the expression of huTFh or pre-huTFh.For example, cells successfully transformed with an expression vectorproduce proteins displaying huTFh or pre-huTFh antigenicity. Samples ofcells suspected of being transformed are harvested and assayed for huTFhor pre-huTFh using antibodies specific for those antigens, such as thoseproduced by a hybridoma of the present invention.

Thus, in addition to the transformed host cells themselves, the presentinvention also contemplates a culture of those cells, preferably amonoclonal (clonally homogeneous) culture, or a culture derived from amonoclonal culture, in a nutrient medium. Preferably, the culture alsocontains a protein displaying huTFh or pre-huTFh antigenicity, and morepreferably, biologically active huTFh.

Nutrient media useful for culturing transformed host cells are wellknown in the art and can be obtained from several commercial sources. Inembodiments wherein the host cell is mammalian, a "serum-free" medium ispreferably used.

E. Methods for Producing huTFh and pre-huTFh Proteins

Another aspect of the present invention pertains to a method forproducing proteins displaying huTFh antigenicity. Proteins that displayhuTFh antigenicity are proteins that immunoreact with antibodies inducedby native tissue factor. Proteins displaying huTFh antigenicity areuseful as antigens and for raising antibodies, each of which can be usedin the diagnostic systems and methods of the present invention.

The present method entails initiating a culture comprising a nutrientmedium containing host cells, preferably human cells, transformed with arecombinant DNA molecule of the present invention that is capable ofexpressing a huTFh or pre-huTFh protein, preferably a soluble huTFh orsoluble pre-huTFh protein. The culture is maintained for a time periodsufficient for the transformed cells to express a huTFh or pre-huTFhprotein. The expressed protein is then recovered from the culture. Inpreferred embodiments, the huTFh proteins produced by the methods of thepresent invention additionally display huTFh biological activity i.e.,the ability to bind factor VII/VIIa. Those methods include culturingmammalian host cells transformed with a recombinant DNA molecule capableof expressing the pre-huTFh gene in the cells. The culturing results inexpression of the pre-huTFh protein and subsequent intracellularpost-translational modification of the pre-huTFh to form a biologicallyactive huTFh protein.

Methods for recovering an expressed protein from a culture are wellknown in the art and include fractionation of the protein-containingportion of the culture using well known biochemical techniques. Forinstance, the methods of gel filtration, gel chromatography,ultrafiltration, electrophoresis, ion exchange, affinity chromatographyand the like, such as are known for protein fractionations, can be usedto isolate the expressed proteins found in the culture. In addition,immunochemical methods, such as immunoaffinity, immunoadsorption and thelike can be performed using well known methods.

F. huTFh and pre-huTFh Protein Compositions and Expression Products

Also contemplated by the present invention are the huTFh and pre-huTFhprotein expression products of the rDNAs of the present invention. Inpreferred embodiments the huTFh and pre-huTFh expression products havean amino acid residue sequence corresponding to residues 1 to 263 and-32 to 263, respectively, as shown in FIG. 1. Preferably, the expressedprotein is at least 90 percent, more preferably at least 95 percent, ofthe length of the pre-huTFh and huTFh amino acid residue sequence lengthshown in FIG. 1.

In another embodiment, soluble forms of huTFh and pre-huTFh andcompositions containing soluble huTFh and/or soluble pre-huTFh arecontemplated. The term "soluble" as used herein refers to huTFh andpre-huTFh molecules characterized as consisting essentially of theextracellular domain of the native huTFh and pre-huTFh molecules, i.e.,that portion of the huTFh and pre-huTFh molecules that is amino-terminalto residue 220 as shown in FIG. 1. Soluble huTFh and soluble pre-huTFhtherefore do not contain any substantial portion of the transmembraneanchor region formed in the native molecules (residues 220 through 242as shown in FIG. 1). It should be noted that the terms "huTFh" and"pre-huTFh" as used herein contemplate and include, unless otherwisespecifically set forth, the soluble forms of those proteins.

Because soluble huTFh and soluble pre-huTFh do not contain a hydrophobictransmembrane anchor region they do not aggregate substantially inphysiologically tolerable aqueous solutions. Therefore, soluble huTFhand soluble pre-huTFh are further characterized by their ability to forman aqueous solution using a physiologically tolerable diluent, atprotein concentration of about 0.1 pg/ml to about 100 ng/ml, wherein atleast about 70, preferably about 80, and more preferably about 90 weightpercent of the huTFh or pre-huTFh protein present is in non-aggregated(monomeric) form. Methods for determining the amount of aggregationpresent in a protein solution are well known in the art and include sizefractionation by exclusion column chromatography.

A preferred soluble huTFh protein has an amino acid residue sequencerepresented by FIG. 1 from about residue 1 at its amino terminus toabout residue 209 through about residue 224 at its carboxy terminus.Thus, preferred soluble huTFh proteins are those having an amino acidresidue sequence represent by FIG. 1 from about residue 1 to aboutresidue 209, from about residue 1 to about residue 214, from aboutresidue 1 to about residue 219, and from about residue 1 to aboutresidue 224.

A preferred soluble pre-huTFh protein has an amino acid residue sequencerepresented by FIG. 1 from about residue -32 at its amino terminus toabout residue 209 through about residue 224 at its carboxy terminus.Thus, preferred soluble pre-huTFh proteins are those having an aminoacid residue sequence represented by FIG. 1 from about residue -32 toabout residue 209, from about residue -32 to about residue 214, fromabout residue -32 to about residue 219, and from about residue -32 toabout residue 224.

In one embodiment, the huTFh and pre-huTFh expression products are notglycosylated, i.e., they are produced in a procaryotic cell transformedwith a rDNA of the present invention. A Non-glycosylated form of huTFhand pre-huTFh is useful as an immunogen and as an antigen in an inoculumand diagnostic system of the present invention.

Eucaryotically produced huTFh and pre-huTFh are typically glycosylatedand biologically active, in addition to being antigenic and immunogenic.As used herein, the phrase "biologically active" refers to a huTFh orpre-huTFh protein or polypeptide having the capacity to induce factorVII/VIIa-dependent coagulation.

Thus, the present invention contemplates a composition comprising anaqueous solution containing biologically active huTFh substantially freeof human tissue factor light chain protein. Preferably, the compositionis also substantially free of entities such as ionic detergents, e.g.,sodium dodecyl sulfate (SDS), polyacrylamide and tissue-derived proteinshaving an apparent molecular weight of less than about 15,000 daltons asdetermined by SDS-polyacrylamide gel electrophoresis (SDS-PAGE).

The aqueous huTFh-containing solutions contain biologically active huTFhin an amount sufficient to assay the coagulation competence of avascular system fluid sample such as blood or blood derived productssuch as citrated plasma. The phrase "coagulation competence" refers tothe ability of the vascular fluid sample to clot in the presence ofbiologically active huTFh. Typical huTFh protein concentrationssufficient to assay for coagulation competence are about 0.1 pg/ml toabout 100 ng/ml, preferably about 1 pg/ml to about 10 ug/ml, and morepreferably about 10 pg/ml to about 1 ng/ml, using sample to huTFh volumeratios similar to those in Example 2. Of course, solutions containinghuTFh at concentrations higher than those required to assay coagulationcompetence but that can be diluted to a preferred concentration are alsocontemplated.

In preferred embodiments, the huTFh-containing aqueous solutions includehuTFh dispersed in a phospholipid or non-ionic detergent. Typicalphospholipid: huTFh-protein weight ratios range from about 5:1 to12,000:1 preferably about 50:1 to about 5,000:1 and more preferablyabout 100:1 to 2,500:1.

G. Polypeptides

The polypeptides of the present invention each contain no more thanabout 50, more usually fewer than about 35 and preferably fewer thanabout 25 amino acid residues, and contains at least about 10 residues.In addition, the polypeptides of the present invention are characterizedby their amino acid residue sequence and novel functional properties.

Thus, one embodiment of a polypeptide of the present invention is ahuTFh binding site polypeptide analog characterized in part by itsability to competitively inhibit the binding of huTF to bloodcoagulation factor VII/VIIa. Preferably, a binding site analog of thepresent invention binds factor VII/VIIa without producing an activatedcomplex, i.e., without initiating coagulation.

The word "complex" as used herein refers to the product of a specificbinding reaction such as an antibody-antigen or receptor-ligandreaction. Exemplary complexes are immunoreaction products and tissuefactor-factor VII/VIIa binding reaction products.

In preferred embodiments, a huTF binding site analog includes at leastthe following amino acid residue sequence:

    --VNQVYT--,

representing amino acid residues 30-35 as shown in FIG. 1.

More preferably, a huTFh binding site analog includes at least one ofthe following amino acid residue sequences:

    --VNQVYTVQIST--,

and

    --LYYWKSSSSGKKT--.

Those sequences represent huTFh amino acid residues 30-40 and 155-167,respectively, as shown in FIG. 1.

Still more preferably, a huTFh binding site analog includes an aminoacid residue sequence chosen from the group consisting of:

    --EPKPVNQVYTVQISTKSGDWKSKC--,

and

    --VFGKDLIYTLYYWKSSSSGKKT--,

representing amino acid residues 26-49 and 146-167, respectively, asshown in FIG. 1.

Preferred huTFh binding site polypeptide analogs include those whoseamino acid residue sequences are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                        Desig-                                                                        nation.sup.a                                                                         Amino Acid Residue Sequence                                            ______________________________________                                        p24-35 H-EWEPKPVNQVYT-OH                                                      p26-49 H-EPKPVNQVYTVQISTKSGDWKSKC-OH                                          p146-167                                                                             H-VFGKDLIYTLYYWKSSSSGKKT-OH                                            p152-169                                                                             H-IYTLYYWKSSSSGKKTAK-OH                                                p161-189                                                                             H-SSSGKKTAKTNTNEFLIDVDKGENYCFSV-OH                                     ______________________________________                                         .sup.a The laboratory designation of each polypeptide represent the           included amino acid residue sequence as shown in FIG. 1.                 

Polypeptides p26-49, p146-167 and p161-189 are also characterized bytheir ability to neutralize (competitively inhibit) the binding ofanti-huTFh antibody molecules to huTFh. Other polypeptides of thepresent invention having the ability to neutralize the biding ofanti-huTFh antibodies to huTFh include those in Table 2.

                                      TABLE 2                                     __________________________________________________________________________    Designation                                                                         Amino Acid Residue Sequences                                            __________________________________________________________________________    p1-30 H-SGTTNTVAAYNLTWKSTNFKTILEWEPKPV-OH                                     p40-71                                                                              H-TKSGDWKSKCFYTTDTECDLTDEIVKDVKQTY-OH                                   p41-49                                                                              H-KSGDWKSKC-OH                                                          p56-71                                                                              H-ECDLTDEIVKDVKQTY-OH                                                   p72-104C.sup.a                                                                      H-LARVFSYPAGNVESTGSAGEPLYENSPEFTPYLC-OH                                 p94-123                                                                             H-YENSPEFTPYLETNLGQPTIQSFEQVGTKV-OH                                     p190-209                                                                            H-QAVIPSRTVNRKSTDSPVEC-OH                                               __________________________________________________________________________     .sup.a The "C" added to the laboratory designation indicates a cysteine       residue was added to the indicated sequence as a linker for protein           conjugation.                                                             

It should be understood that a polypeptide of the present invention neednot be identical to the amino acid residue sequence of huTFh, so long asthe subject polypeptides are able to compete with native tissue factorfor binding to factor VII/VIIa and/or are able to competitively inhibitthe binding of anti-huTFh antibody molecules to huTFh. Therefore, apresent polypeptide can be subject to various changes, such asinsertions, deletions and substitutions, either conservative ornon-conservative, where such changes provide for certain advantages intheir use.

Conservative substitutions are those where one amino acid residue isreplaced by another, biologically similar residue. Examples ofconservative substitutions include the substitution of one hydrophobicresidue such as isoleucine, valine, leucine or methionine for another,or the substitution of one polar residue for another such as betweenarginine and lysine, between glutamic and aspartic acids or betweenglutamine and asparagine and the like. The term "conservativesubstitution" also includes the use of a substituted amino acid in placeof an unsubstituted parent amino acid provided that such a polypeptidealso displays the requisite binding activity.

When a polypeptide of the present invention has a sequence that is notidentical to the sequence of native huTFh because one or moreconservative or non-conservative substitutions have been made, usuallyno more than about 20 number percent and more usually no more than 10number percent of the amino acid residues are substituted, except whereadditional residues have been added at either terminus for the purposeof providing a "linker" by which the polypeptides of this invention canbe conveniently affixed to a label or solid matrix, or carrier. Labels,solid matrices and carriers that can be used with the polypeptides ofthis invention are described hereinbelow.

Amino acid residue linkers are usually at least one residue and can be40 or more residues, more often 1 to 10 residues. Typical amino acidresidues used for linking are tyrosine, cysteine, lysine, glutamic andaspartic acid, or the like. In addition, a polypeptide sequence of thisinvention can differ from the natural sequence by the sequence beingmodified by terminal-NH2 acylation, e.g., acetylation, or thioglycolicacid amidation, terminal-carboxlyamidation, e.g., ammonia, methylamine,etc.

When coupled to a carrier via a linker to form what is known in the artas a carrier-hapten conjugate, a polypeptide of the present invention iscapable of inducing antibodies that immunoreact with huTFh. In view ofthe well established principle of immunologic cross-reactivity, thepresent invention therefore contemplates antigenically related variantsof the polypeptides shown in Tables 1 and 2. An "antigenically relatedvariant" is a polypeptide that includes at least a six amino acidresidue sequence portion of a polypeptide from Table 1 or Table 2 andwhich is capable of inducing antibody molecules that immunoreact with apolypeptide from Table 1 or 2 and huTFh.

Also contemplated by the present invention is a composition comprisingan aqueous solution of a huTFh binding site polypeptide analog whereinthe polypeptide is dispersed in a phospholipid or non-ionic detergent.Typical phospholipid: polypeptide analog weight ratios range from about5:1 to 200:1, preferably from about 30:1 to 80:1 and more preferablyabout 45:1 to 55:1. Preferred huTFh binding site polypeptide analogssuitable for use dispersed in a phospholipid are those listed in Table4, section II.

A polypeptide of the present invention can be synthesized by anytechniques that are known to those skilled in the polypeptide art. Anexcellent summary of the many techniques available may be found in J. M.Steward and J. D. Young, "Solid Phase Peptide Synthesis", W. H. FreemanCo., San Francisco, 1969, and J. Meienhofer, "Hormonal Proteins andPeptides", Vol. 2, p. 46, Academic Press (New York), 1983 for solidphase peptide synthesis, and E. Schroder and K. Kubke, "The Peptides",Vol. 1, Academic Press (New York), 1965 for classical solutionsynthesis.

H. Inocula

In another embodiment, a polypeptide of this invention or anantigenically related variant thereof is used in a pharmaceuticallyacceptable aqueous diluent composition to form an inoculum that, whenadministered in an effective amount, is capable of inducing antibodiesthat immunoreact with huTFh. The word "inoculum" in its variousgrammatical forms is used herein to describe a composition containing apolypeptide of this invention as an active ingredient used for thepreparation of antibodies against huTFh. When a polypeptide is used toinduce antibodies it is to be understood that the polypeptide can beused alone, or linked to a carrier as a conjugate, or as a polypeptidepolymer, but for ease of expression the various embodiments of thepolypeptides of this invention are collectively referred to herein bythe term "polypeptide", and its various grammatical forms.

For a polypeptide that contains fewer than about 35 amino acid residues,it is preferable to use the peptide bound to a carrier for the purposeof inducing the production of antibodies as already noted.

As already noted, one or more additional amino acid residues can beadded to the amino- or carboxy-termini of the polypeptide to assist inbinding the polypeptide to a carrier. Cysteine residues added at theamino- or carboxy-termini of the polypeptide have been found to beparticularly useful for forming conjugates via disulfide bonds. However,other methods well known in the art for preparing conjugates can also beused. Exemplary additional linking procedures include the use of Michaeladdition reaction products, di-aldehydes such as glutaraldehyde,Klipstein et al., J. Infect. Dis., 147, 318-326 (1983) and the like, orthe use of carbodiimide technology as in the use of a water-solublecarbodiimide to form amide links to the carrier. For a review of proteinconjugation or coupling through activated functional groups, seeAurameas, et al., Scand. J. Immunol., Vol. 8, Supp-1. 7, 7-23 (1978).

Useful carriers are well known in the art, and are generally proteinsthemselves. Exemplary of such carriers are keyhole limpet hemocyanin(KLH), edestin, thyroglobulin, albumins such as bovine serum albumin(BSA) or human serum albumin (HSA), red blood cells such as sheeperythrocytes (SRBC), tetanus toxoid, cholera toxoid as well as polyaminoacids such as poly (D-lysine: D-glutamic acid), and the like.

The choice of carrier is more dependent upon the ultimate use of theinoculum and is based upon criteria not particularly involved in thepresent invention. For example, a carrier that does not generate anuntoward reaction in the particular animal to be inoculated should beselected.

The present inoculum contains an effective, immunogenic amount of apolypeptide of this invention, typically as a conjugate linked to acarrier. The effective amount of polypeptide per unit dose depends,among other things, on the species of animal inoculated, the body weightof the animal and the chosen inoculation regimen as is well known in theart. Inocula typically contain polypeptide concentrations of about 10micrograms to about 500 milligrams per inoculation (dose), preferablyabout 50 micrograms to about 50 milligrams per dose.

The term "unit dose" as it pertains to the inocula of the presentinvention refers to physically discrete units suitable as unitarydosages for animals, each unit containing a predetermined quantity ofactive material calculated to produce the desired immunogenic effect inassociation with the required diluent; i.e., carrier, or vehicle. Thespecifications for the novel unit dose of an inoculum of this inventionare dictated by and are directly dependent on (a) the uniquecharacteristics of the active material and the particular immunologiceffect to be achieved, and (b) the limitations inherent in the art ofcompounding such active material for immunologic use in animals, asdisclosed in detail herein, these being features of the presentinvention.

Inocula are typically prepared from the dried solidpolypeptide-conjugate by dispersing the polypeptide-conjugate in aphysiologically tolerable (acceptable) diluent such as water, saline orphosphate-buffered saline to form an aqueous composition.

Inocula can also include an adjuvant as part of the diluent. Adjuvantssuch as complete Freund's adjuvant (CFA), incomplete Freund's adjuvant(IFA) and alum are materials well known in the art, and are availablecommercially from several sources.

I. Antibodies and Antibody Compositions

The term "antibody" in its various grammatical forms is used herein torefer to immunoglobulin molecules and immunologically active portions ofimmunoglobulin molecules, i.e., molecules that contain an antibodycombining site or paratope. Exemplary antibody molecules are intactimmunoglobulin molecules, substantially intact immunoglobulin moleculesand those portions of an immunoglobulin molecule that contain theparatope, including those portions known in the art as Fab, Fab',F(ab')₂ and F(v).

An antibody composition of the present invention is characterized ascontaining antibody molecules that immunoreact with huTFh and at leastone specific polypeptide of this invention.

For instance, an antibody composition of the present inventioncontaining antibody molecules that immunoreact with huTFh and apolypeptide analog of the tissue factor binding site, but do notsubstantially immunoreact with p204-226, is capable of neutralizing theability of tissue factor to bind factor VII/VIIa. Thus, preferredantibody compositions are those containing antibody molecules thatimmunoreact with huTFh and p26-49 or p146-167, and are substantiallyfree from immunoreaction with p204-226.

It should be noted that polyclonal antisera raised to huTFh containantibodies that immunoreact with p204-226. Thus, the substantial absenceof anti-p204-226 immunoreactivity is a feature that distinguishes thepresent antibody compositions from those described in the art.

An antibody composition of the present invention is typically producedby immunizing a mammal with an inoculum of the present invention andthereby induce in the mammal antibody molecules having the appropriatepolypeptide immunospecificity. The antibody molecules are then collectedfrom the mammal and isolated to the extent desired by well knowntechniques such as, for example, by immunoaffinity chromatography. Theantibody composition so produced can be used in, inter alia, thediagnostic methods and systems of the present invention to detect huTFhin a body sample.

Monoclonal antibody compositions are also contemplated by the presentinvention. A monoclonal antibody composition contains, within detectablelimits, only one species of antibody combining site capable ofeffectively binding huTFh. Thus, a monoclonal antibody composition ofthe present invention typically display a single binding affinity forhuTFh even though it may contain antibodies capable of binding proteinsother than huTFh. In one embodiment, a monoclonal antibody compositioncontains antibody molecules that immunoreact with huTFh and apolypeptide analog of the tissue factor binding site, preferably p26-49or p146-167. The antibody molecules contained in these compositionsimmunoreact with huTFh at or near its factor VII/VIIa binding site andthereby neutralize its ability to bind factor VII/VIIa.

The present invention also contemplates a monoclonal antibodycomposition containing antibody molecules that do not neutralize theability of tissue factor to bind factor VII/VIIa. Such a compositioncontains antibody molecules that immunoreact with huTFh and thepolypeptide p1-30 and is produced (secreted) by hybridoma TF9-10H10.

A monoclonal antibody composition of the present invention can beproduced by initiating a monoclonal hybridoma culture comprising anutrient medium containing a hybridoma that secretes antibody moleculesof the appropriate polypeptide specificity.

The culture is maintained under conditions and for a time periodsufficient for the hybridoma to secrete the antibody molecules into themedium. The antibody-containing medium is then collected. The antibodymolecules can then be further isolated by well known techniques.

Media useful for the preparation of these compositions are both wellknown in the art and commercially available and include syntheticculture media, inbred mice and the like. An exemplary synthetic mediumis Dulbecco's minimal essential medium (DMEM; Dulbecco et al., Virol.8:396 (1959)) supplemented with 4.5 gm/l glucose, 20 mm glutamine, and20% fetal calf serum. An exemplary inbred mouse strain is the Balb/c.The monoclonal antibody compositions produced by the above method can beused, for example, in diagnostic and therapeutic modalities whereinformation of an huTFh-containing immunoreaction product is desired.

J. Hybridomas

The hybridomas of the present invention are characterized as producingantibody molecules that immunoreact with huTFh and either a polypeptideanalog of the tissue factor binding site or p204-226.

Methods for producing hybridomas producing (secreting) antibodymolecules having a desired immunospecificity, i.e., having the abilityto immunoreact with a particular protein and/or polypeptide, are wellknown in the art. Particularly applicable is the hybridoma technologydescribed by Niman et al., Proc. Natl. Acad. Sci. U.S.A., 80:4949-4953(1983). Preferred hybridomas are those shown in Table 5 in Example 13.

Hybridoma cultures TF8-5G9,, TF9-6B4 and TF9-10H10 have been depositedpursuant to Budapest Treaty requirements with the ATCC on Mar. 27, 1987,and were assigned the following respective accession numbers HB9382,HB9381 and HB9383.

K. Therapeutic Methods and Compositions

The huTFh factor VII/VIIa binding site polypeptide analogs, antibodycompositions and monoclonal antibody compositions of the presentinvention each can be used to modulate the binding of factor VII/VIIa bytissue factor in vivo.

For instance, a huTFh factor VII/VIIa binding site polypeptide analogcan be used in a pharmaceutically acceptable composition that, whenadministered to a human subject in an effective amount, is capable ofcompetitively inhibiting the binding of factor VII/VIIa to tissuefactor. That inhibition is believed to result in a decreased rate oftissue factor-factor VII/VIIa complex formation. Thus, in vivoadministration of an huTFh factor VII/VIIa binding site polypeptideanalog can be used to modulate any physiological response initiated bytissue factor binding to factor VII/VIIa, such as coagulation and someinflammatory responses. In preferred embodiments, the polypeptide isadministered when dispersed in a phospholipid as previously described.

Another approach to modulating the binding of factor VII/VIIa by tissuefactor in vivo is to intravenously administer an effective amount of acomposition containing antibody molecules that immunoreact with huTFh,preferably with those that bind at or near huTFh's factor VII/VIIabinding site, i.e., antibody molecules that bind a huTFh factor VII/VIIabinding site polypeptide analog. Preferably the antibody molecules arethose that contain the paratopic region and are free from the Fc region,such as immunoglobulin fragments F(ab')₂, Fab and the like.

In another embodiment, a monoclonal antibody composition of the presentinvention contains antibody molecules that immunoreact with huTFh and ahuTFh binding site polypeptide analog wherein the antibody molecules arelinked to an anti-tumor agent. An effective amount of anti-tumortherapeutic composition thus formed can be administered to a humansubject having tumor cells that expresses tissue factor on theirsurface. Exemplary of such tumor cells are carcinomas of the breast andlung.

Typical of the anti-tumor agents contemplated herein are radionuclidessuch as ¹³¹ I, ¹⁸⁸ Re, ²¹² Bi and the like. Methods for producingradionuclide-conjugated monoclonal antibody therapeutic compositions andtheir use are described in Kozak et al., Trends In Biotech., 4:259-264(1986).

The polypeptide- or antibody molecule-containing compositionsadministered take the form of solutions or suspensions, however,polypeptides can also take the form of tablets, pills, capsules,sustained release formulations or powders. In any case, the compositionscontain 10%-95% of active ingredient, preferably 25-70%.

The preparation of therapeutic compositions which contain polypeptidesor antibody molecules as active ingredients is well understood in theart. Typically, such compositions are prepared as injectables, either asliquid solutions or suspensions, however, solid forms suitable forsolution in, or suspension in, liquid prior to injection can also beprepared. The preparation can also be emulsified. The active therapeuticingredient is often mixed with excipients which are pharmaceuticallyacceptable and compatible with the active ingredient. Suitableexcipients are, for example, water, saline, dextrose, glycerol, ethanol,or the like and combinations thereof. In addition, if desired, thecomposition can contain minor amounts of auxiliary substances such aswetting or emulsifying agents, pH buffering agents which enhance theeffectiveness of the active ingredient.

A polypeptide or antibody molecule composition can be formulated intothe therapeutic composition as neutralized pharmaceutically acceptablesalt forms. Pharmaceutically acceptable salts include the acid additionsalts (formed with the free amino groups of the polypeptide or antibodymolecule) and which are formed with inorganic acids such as, forexample, hydrochloric or phosphoric acids, or such organic acids asacetic, oxalic, tartaric, mandelic, and the like. Salts formed with thefree carboxyl groups can also be derived from inorganic bases such as,for example, sodium, potassium, ammonium, calcium, or ferric hydroxides,and such organic bases as isopropylamine, trimethylamine, 2-ethylaminoethanol, histidine, procaine, and the like.

The therapeutic polypeptide- or antibody molecule-containingcompositions are conventionally administered intravenously, as byinjection of a unit dose, for example. The term "unit dose" when used inreference to a therapeutic composition of the present invention refersto physically discrete units suitable as unitary dosages for humans,each unit containing a predetermined quantity of active materialcalculated to produce the desired therapeutic effect in association withthe required diluent; i.e., carrier, or vehicle.

The compositions are administered in a manner compatible with the dosageformulation, and in a therapeutically effective amount. The quantity tobe administered depends on the subject to be treated, capacity of thesubject's blood coagulation system to utilize the active ingredient, anddegree of inhibition or neutralization of tissue factor binding capacitydesired. Precise amounts of active ingredient required to beadministered depend on the judgment of the practitioner and are peculiarto each individual. However, suitable dosage ranges are of the order ofone to several milligrams of active ingredient per individual per dayand depend on the route of administration. Suitable regimes for initialadministration and booster shots are also variable, but are typified byan initial administration followed by repeated doses at one or more hourintervals by a subsequent injection or other administration.Alternatively, continuous intravenous infusion sufficient to maintainconcentrations of ten nanomolar to ten micromolar in the blood arecontemplated.

L. Diagnostic Systems

A diagnostic system in kit form of the present invention includes, in anamount sufficient for at least one assay, an expressed protein,polypeptide, antibody composition or monoclonal antibody composition ofthe present invention, as a separately packaged reagent. Instructionsfor use of the packaged reagent are also typically included.

"Instructions for use" typically include a tangible expressiondescribing the reagent concentration or at least one assay methodparameter such as the relative amounts of reagent and sample to beadmixed, maintenance time periods for reagent/sample admixtures,temperature, buffer conditions and the like.

In preferred embodiments, a diagnostic system of the present inventionfurther includes a label or indicating means capable of signaling theformation of a complex containing a reagent species.

As used herein, the terms "label" and "indicating means" in theirvarious grammatical forms refer to single atoms and molecules that areeither directly or indirectly involved in the production of a detectablesignal to indicate the presence of a complex. "In vivo" labels orindicating means are those useful within the body of a human subject.Any label or indicating means can be linked to or incorporated in anexpressed protein, polypeptide, or antibody molecule that is part of anantibody or monoclonal antibody composition of the present invention, orused separately, and those atoms or molecules can be used alone or inconjunction with additional reagents. Such labels are themselveswell-known in clinical diagnostic chemistry and constitute a part ofthis invention only insofar as they are utilized with otherwise novelproteins methods and/or systems.

The linking of labels, i.e., labeling of, polypeptides and proteins iswell known in the art. For instance, antibody molecules produced by ahybridoma can be labeled by metabolic incorporation ofradioisotope-containing amino acids provided as a component in theculture medium. See, for example, Galfre et al., Meth. Enzymol., 73:3-46(1981). The techniques of protein conjugation or coupling throughactivated functional groups are particularly applicable. See, forexample, Aurameas, et al., Scand. J. Immunol., Vol. 8 Suppl. 7:7-23(1978), Rodwell et al., Biotech., 3:889-894 (1984), and U.S. Pat. No.4,493,795.

The diagnostic systems can also include, preferably as a separatepackage, a specific binding agent. A "specific binding agent" is amolecular entity capable of selectively binding a reagent species of thepresent invention but is not itself a protein expression product,polypeptide, or antibody molecule of the present invention. Exemplaryspecific binding agents are antibody molecules, complement proteins orfragments thereof, protein A, blood coagulation factor VII/VIIa, bovinetissue factor and the like. Preferably the specific binding agent canbind the reagent species when the species is present as part of acomplex.

In preferred embodiments the specificbinding agent is labeled. However,when the diagnostic system includes a specific binding agent that is notlabeled, the agent is typically used as an amplifying means or reagent.In these embodiments, the labeled specific binding agent is capable ofspecifically binding the amplifying means when the amplifying means isbound to a reagent species-containing complex.

The diagnostic kits of the present invention can be used in an "ELISA"format to detect the presence or quantity of huTFh in a body fluidsample such as serum, plasma or urine. "ELISA" refers to anenzyme-linked immunosorbent assay that employs an antibody or antigenbound to a solid phase and an enzyme-antigen or enzyme-antibodyconjugate to detect and quantify the amount of an antigen or antibodypresent in a sample. A description of the ELISA technique is found inChapter 22 of the 4th Edition of Basic and Clinical Immunology by D. P.Sites et al., published by Lange Medical Publications of Los Altos,Calif. in 1982 and in U.S. Pat. Nos. 3,654,090; 3,850,752; and4,016,043, which are all incorporated herein by reference.

Thus, in preferred embodiments, the expressed protein, polypeptide, orantibody molecule of the present invention can be affixed to a solidmatrix to form a solid support that is separately packaged in thesubject diagnostic systems.

The reagent is typically affixed to the solid matrix by adsorption froman aqueous medium although other modes of affixation, well known tothose skilled in the art can be used.

Useful solid matrices are well known in the art. Such materials includethe cross-linked dextran available under the trademark SEPHADEX fromPharmacia Fine Chemicals (Piscataway, N.J.); agarose; beads ofpolystyrene beads about 1 micron to about 5 millimeters in diameteravailable from Abbott Laboratories of North Chicago, Ill.; polyvinylchloride, polystyrene, cross-linked polyacrylamide, nitrocellulose- ornylon-based webs such as sheets, strips or paddles; or tubes, plates orthe wells of a microtiter plate such as those made from polystyrene orpolyvinylchloride.

The reagent species, labeled specific binding agent or amplifyingreagent of any diagnostic system described herein can be provided insolution, as a liquid dispersion or as a substantially dry power, e.g.,in lyophilized form. Where the indicating means is an enzyme, theenzyme's substrate can also be provided in a separate package of asystem. A solid support such as the before-described microtiter plateand one or more buffers can also be included as separately packagedelements in this diagnostic assay system.

The packages discussed herein in relation to diagnostic systems arethose customarily utilized in diagnostic systems. Such packages includeglass and plastic (e.g., polyethylene, polypropylene and polycarbonate)bottles, vials, plastic and plastic-foil laminated envelopes and thelike.

M. Assay Methods

The present invention contemplates any method that results in detectinghuTFh by producing a complex containing an expressed protein,polypeptide or antibody molecule contained in an antibody or monoclonalantibody composition of the present invention. Those skilled in the artwill understand that there are numerous well known clinical diagnosticchemistry procedures that can be utilized to form those complexes. Thus,while exemplary assay methods are described herein, the invention is notso limited.

1. Thrombus Detection

A method for detecting the presence of a thrombus in a human subject iscontemplated. An effective amount of a monoclonal antibody compositionof the present invention containing antibody molecules linked to an invivo indicating means is intravenously administered into the subject. Inpreferred embodiments the labeled antibody molecules are those thatimmunoreact with huTFh and a polypeptide from Tables 1 and 2 but notp204-226, more preferably those produced by hybridoma TF8-5G9, TF9-6B4or TF9-10H10.

The subject is then maintained for a predetermined time periodsufficient for the labeled antibody molecules to react with huTFhpresent part of a thrombus and form a complex and preferably for anadditional time period sufficient for a substantial amount of anynon-reacted antibody molecules to clear the body. The subject is thenassayed for the presence and preferably location of any complex thatformed.

2. Detection of huTFh in a Body Sample

Various heterogeneous and homogeneous assay protocols can be employed,either competitive or non-competitive for detecting the presence andpreferably amount of huTFh in a body sample preferably a body fluidsample. For example, a liquid body fluid sample and labeled p26-49 areadmixed with a solid support comprising antibody molecules produced byhybridoma TF8-5G9 or TF9-10H10 affixed to the inner wall of a microtiterplate well to form a solid-liquid phase immunoreaction admixture. Theadmixture is maintained under biological assay conditions for a timeperiod sufficient for any huTFh present in the sample and labeled p26-49to compete for binding to the antibody molecules present as solidsupport and form a solid phase immunoreaction product. The unboundlabeled p26-49 is then separated from the immunoreaction products. Theamount of labeled p26-49 bound as immunoreaction product is thendetermined, and thereby provides, by difference, a measure of thepresence of huTFh.

EXAMPLES

The following examples are intended to illustrate, but not limit, thepresent invention.

1. Preparation of Tissue Factor-Containing Human Brain-Extract

Normal human brains obtained at autopsy were either processed within 12hours or stored frozen at minus 80 degrees Centigrade (C). The meningesand cerebellum were removed and the remaining brain portions werehomogenized in an equal volume of cold (0 degrees C) acetone using aPolytron homogenizer (Brinkman Instruments, Co., Westbury, N.Y.). Theresulting homogenate was admixed with an additional 3 volumes of coldacetone, and the tissue-solids fraction was recovered by filtrationusing a sintered glass funnel. Acetone soluble material was extractedfrom the retained solids seven additional times, each by admixing withtwo volumes of cold acetone and subsequent filtration. After the finalfiltration, residual acetone was allowed to evaporate at atmosphericpressure from the retained solids overnight at about 20 degrees C.

The retained brain tissue-solids were then subjected to 5 extractions,each performed by admixing the solids with a 2:1 heptane:butanolsolution at a ratio of 1 gram tissue-solids per 25 milliliter (ml)heptane:butanol, followed by filtration to recover the solids. After thefinal filtration the retained brain tissue-solids were again driedovernight at about 20 degrees C under atmospheric pressure to form adelipidated brain tissue powder that was stored at minus 80 degrees Cuntil needed.

Twenty-five grams of the brain tissue power were subsequently admixedwith 500 ml of TS/EDTA buffer [100 millimolar (mM) NaCl, 50 mM Tris-HCl(pH 7.5), 0.02% sodium azide, 5 mM ethylenediaminetetraacetic acid(EDTA), 0.1% (v/v) Triton X-100 (polyarylethylene 9 octyl phenyl ether)]and stirred overnight at 4 degrees C. The admixture was then centrifugedat 15,300 × g for 1 hour. The resulting pellet was resuspended in 500 mlof Buffer A [100 mM NaCl, 50 mM Tris-HCl (pH 7.5), 0.02% sodium azide,2% Triton X-100] to form a slurry. After stirring for 1 hour at roomtemperature, the slurry was centrifuged as described above. Theresulting supernatant was recovered, lyophilized and subsequentlysolubilized in 100 ml of Buffer A to form a huTF-containingbrain-extract solution.

2. Coagulation Assay to Measure huTF Procoagulant Activity

huTF procoagulant activity was measured in a one stage coagulation assayperformed with all reagents and admixtures maintained at 37 degrees C. Apool of normal human plasma was citrated by admixing 1 volume of plasmawith 1 volume of a solution containing 20 mM sodium citrate dihydrateand 140 mM NaCl, pH 7.4. One hundred microliters of a sample containinghuTF diluted in TBS/BSA solution (150 mM NaCl, 50 mM Tris-HCl, pH 7.5,0.1% bovine serum albumin) was admixed with 100 ul of the citratedplasma. One hundred ul of a 25 mM CaCl₂ solution were then admixed toform a coagulation reaction admixture that was rocked gently untilcoagulation occurred. The time between the addition of CaCl₂ and clotformation was measured. A standard curve of huTF activity was thenconstructed by plotting dilution versus coagulation time in seconds. Anexemplary standard curve is shown in FIG. 3.

3. Preparation of a Factor VII Containing Solid Support for AffinityIsolation of huTF

Human factor VII/VIIa was isolated as described by Fair, Blood,62:784-91 (1983), which is hereby incorporated by reference. Thisisolated factor VII/VIIa was activated for coupling to an agarose solidmatrix by dialyzing 5 milligrams (mg) against 0.1M2-(N-Morpholino)ethanesulfonic acid (MES) (pH 6.5), overnight at 4degrees C. Calcium chloride was added to a final concentration of 1 mM.factor VII/VIIa was then admixed with 4 mls of AffiGel-15 activatedagarose beads (Biorad Laboratories, Richmond, Calif.) and the resultingcoupling-reaction mixture was processed by rotation for 4 hours at 4degrees C according to the manufacturer's recommendations (Biorad).

Excess protein binding sites on the solid support were blocked by gentlyagitating the solid support in 0.1M glycine ethyl ester for one hour atroom temperature. Thereafter, the solid support was washed sequentiallyon a sintered glass funnel with about 20 ml each of (1) Buffer A, (2)Buffer A containing 1M NaCl, (3) Buffer A containing 5 mM EDTA, and (4)Buffer A containing 1 mM CaCl₂. Excess liquid was then removed by vacuumto form a semi-dry particulate mass (cake).

4. Factor VII/VIIa-Affinity Isolation of huTF

Twenty ml of a solution containing 0.1M glycine ethyl ester and 0.1MMES, pH 6.5 was admixed with 22.5 ml of Affigel-15 agarose beads(Biorad) to form a coupling reaction admixture. The coupling reactionadmixture was maintained at room temperature for 1 hour. The resultingconjugate was washed on a sintered glass funnel 4 times with 10 volumesof Buffer 1 filtered under vacuum to form a glycine ethyl ester-agarosecake.

Thirty mls of brain-extract solution prepared in Example 1 were dialyzedovernight at 4 degrees C against 6 liters of Buffer A containing 1 mMcalcium chloride. Dialyzed brain extract was admixed with the glycineethyl ester-agarose cake to form a solid-liquid phase reactionadmixture. After being maintained for 2 hours at room temperature withrotation, the solid and liquid phases were separated by filtration usinga sintered glass funnel. The liquid phase was recovered and admixed withTrasylol (aprotinin; Sigma Chemical Co. St. Louis, Mo.) to a finalconcentration of 10 units per ml. The recovered liquid phase was admixedwith the factor VII/VIIa/agarose cake prepared in Example 3 to form asecond solid/liquid phase admixture.

This admixture was maintained overnight at 4 degrees C with rotation toallow formation of a huTF-factor VII/VIIa-containing solid phaseproduct. The solid and liquid phases were then separated by filtrationas previously described. The solid phase retained on the sintered glassfunnel was washed with 25 mls of Buffer A containing 1 mM calciumchloride. The solid phase was then transferred to a sintered glasschromatography column (0.5×15 cm; Biorad) and washed with 6 mls of thesame wash buffer. Any huTF bound to the solid support after the abovewashes was then released (eluted) by washing the solid support whileretained upon the sintered glass column Buffer A containing 5 mM EDTA.Eluted material was collected in 1 ml fractions and each fraction wasassayed for the presence of huTF as described in Example 2.huTF-containing fractions were pooled and dialyzed overnight against 6liters of TBS containing 1% Triton X-100 (TBS/Triton) at 4 degrees C.

The dialysate thus formed was subsequently admixed with four volumes ofcold acetone to precipitate the huTF protein. The precipitate was thecollected by centrifugation at 5,000 times g for 30 minutes atapproximately minus 10 degrees C. The resulting pellet was dried undernitrogen. Typical yields were 2 ug of huTF per gram (dry weight) ofdelipidated brain tissue powder.

A sample of the isolated huTF thus formed was suspended in TBS/Tritonand then labeled with Na¹²⁵ I (16 micro Curies per microgram, Amersham,Arlington Heights, Ill.) using Iodogen according to the manufacturer'sdirections (Pierce Chemical Co., Rockford, Ill.). After labeling, excessunreacted ¹²⁵ I was separated from the labeled huTF by desaltingchromatography on Sephadex G25 (Pharmacia, Inc., Piscataway, N.J.) usingTBS/Triton.

¹²⁵ I-labeled huTF-containing samples were evaluated by sodiumdodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) accordingto Laemmli, Nature, 227:680-685 (1970). Dithiothreitol (DTT, Sigma) wasincluded in the sample buffer at 100 mM for those samples evaluatedunder reducing conditions. Immunoprecipitations were performed byincubating overnight at 4 degrees C ¹²⁵ I-huTF in 1% Triton X100, 50 mMTris-HCl (pH 7.4), 150 mM NaCl with 1/10 volume of TF8-5G9 or PAb 100(ATCC TIB 115; a hybridoma producing a SV40 large T antigen specificantibody used here as a negative control) hybridoma culture supernatant.Goat anti-mouse IgG immobilized on agarose beads (Sigma Chemical Co.,St. Louis, Mo.) was then used to adsorb the primary immunoreactionproducts. The beads were washed extensively with the same buffer and thebound ¹²⁵ I-huTF was eluted by boiling for 5 minutes in sample bufferwith or without DTT. Protein bands were visualized after SDS-PAGE byautofluoragraphy.

When isolated huTF was radioiodinated, reduced with DTT, and analyzed bySDS-PAGE on 10% acrylamide gels, a single major band with an apparentmolecular mass of 47 kDa was observed (FIG. 4). However, when unreducedhuTF was similarly analyzed, two bands of approximately 58 and 47 kDawere observed in relatively equal abundance (FIG. 5, lane B), suggestingat least two different size forms.

Possible explanations for the two bands observed in the absence ofreduction were that the larger, i.e. slower migrating band, could bemore highly glycosylated, may possess additional unprocessed protein, ormight be associated with additional, disulfide-bond linked polypeptides.The presence of a single band following reduction was inconsistent withthe first two suggestions. The latter possibility appeared most likely,but because of the small size difference, additional polypeptide chainswould probably be small enough to migrate at or near the dye front andnot be resolved by 10% acrylamide gels following reduction.Electrophoresis of reduced and non-reduced huTF on 15% polyacrylamidegels failed to show a single discrete light chain, although severalminor, rapidly migrating bands were observed (FIG. 5, lanes A and B).These small, minor polypeptides could represent contaminants which havepreviously been noted [Broze et al., J. Biol. Chem., 260:10917-20 (1985)and Guha et al., Proc. Natl. Acad. Sci. U.S.A. 83:299-302 (1986)]. Toclearly resolve the possibilities, the 47 kDa and 58 kDa bands wereexcised from the non-reduced gel, and each was reduced withdithiothreitol and individually subjected to SDS-PAGE on a 15%acrylamide gel (FIG. 5, lanes C and D). The 58 kDa protein was resolvedas a 12.5 kDa light chain and a 47 kDa heavy chain. When the 47 kDaprotein was examined, only a heavy chain of the same molecular weightwas observed. Thus both forms possessed heavy chains of similar behavioron SDS-PAGE.

In order to demonstrate the presence of the light chain directly, ¹²⁵I-huTF was immunoprecipitated with the huTF-specific monoclonal antibodyTF8-5G9 and subjected to electrophoresis in the presence of reducingagent. The major 47 kDa band was observed along with a discrete band ofapproximately 12.5 kDa (FIG. 6, lane A). Electrophoresis of the samplewithout prior reduction yielded bands of approximately 47 kDa and 58kDa, but no low molecular weight polypeptide (FIG. 6, lane B).Electrophoresis of non-reduced huTF also yielded minor quantities of 90kDa protein, consistent with a dimer of the huTF heavy chain which hasbeen suggested by Broze et al., J. Biol. Chem. 260:10917-20 (1985).

To investigate the possibility that the huTF light chain might bederived proteolytically from the heavy chain the SDS-PAGE isolated lightand heavy chains were subjected to N-terminal amino acidsequenceanalysis.

Heavy and light chains were resolved on SDS-PAGE and electroblotted ontoactivated, amino-derivatized fiberglass filters using the high pH methodof Abersold et al., J. Biol. Chem., 261:4229-4238 (1986). The proteinbands were visualized on the blots by fluorescent staining Abersold etal., supra, excised, and sequenced, still bound to the fiberglass, in anApplied Biosystems 470A protein sequencer with on-line HPLC analysis ofPTH derivatives. Alternatively, the protein bands were visualized on thegel by staining with Coomassie blue and electroeluted for sequencing.Both methods gave equivalent results.

Microsequencing of the huTF heavy chain consistently resulting in twosimultaneous amino acid sequences in roughly equimolar amounts. Inalmost all cases, each amino acid residue appeared twice, two cyclesapart. This is clear evidence for staggered N-termini of two variants ofhuTF heavy chain, which differ in length at the N-terminus by tworesidues. The N-terminus of the larger variant was deduced to beSer-Gly-X-X-Asn-Thr-Val-Ala-Ala-Tyr-X-Leu-Thr-Trp-Lys-Ser, wherein Xrepresents an unspecified amino acid residue.

Several attempts to sequence the light chain yielded no sequenceinformation, consistent with a blocked N-terminus. However, the heavyand light chain of huTF are antigenically distinct, since two rabbitanti-huTF antisera and twenty-eight murine monoclonal antibodies raisedagainst isolated huTFh were all found to bind to the heavy chain alone.Therefore, the light chain is unlikely to be a proteolytic fragment ofthe heavy chain. In addition, the light chain did not react withantisera to β₂ microglobulin.

The significance of the 12.5 kDa huTF light chain is presently unknown.It is unlikely to be derived artifactually during isolation by randomdisulfide exchange, since it is a single, discrete molecular species.When affinity isolated huTF was subjected to SDS-PAGE without reduction,huTF activity was eluted from gels corresponding to both the 58 kDa and47 kDa molecular weight forms. huTF activity corresponding to those twomolecular weight forms was also detected when crude brain or partiallyisolated placental extracts were subjected to electrophoresis on SDSgels (data not shown). In all cases the activity was factorVII-dependent, thus indicating huTF specific activity. These findingsindicate that huTFh alone can activate factor VII and that the lightchain is not required for this function.

It is of interest that the light chain is disulfide-bonded to only abouthalf of the huTF heavy chains. Either it is absent in vivo from asignificant proportion of huTF or is present, but associated vianon-covalent interactions that are disruptible by detergents. The lightchain of huTF may have gone unnoticed in earlier studies because itssmall size would result in migration at the dye front in SDS-PAGE, andbecause published analyses of huTF have been performed followingreduction. The limited quantities which can be isolated using currentaffinity methods makes it difficult to detect an associated smallpolypeptide chain by protein staining.

Although monomeric huTF will initiate coagulation in vitro, physiologicinitiation of coagulation by huTF occurs on cell surfaces. One mayspeculate that the light chain may play more subtle roles in huTFfunction or organization than can be detected in a straightforwardcoagulation assay. For example, the light chain may be involved in theassembly of the two-subunit receptor for factor VII which has beenhypothesized to explain the apparent positive cooperactivity of bindingof factor VII/VIIa to tissue factor. Alternatively, organization of huTFin structural domains on the cell surface and regulation of huTFactivity on cell surfaces may be mediated by the huTF light chainmolecule.

The role of N-linked oligosaccharides was examined by deglycosylating asample of the ¹²⁵ I-huTF. About 12.74 nanograms (ng) of labeled juTFcontaining approximately 3.6×10⁵ counts per minute (cpm) were admixedwith 20 ul of a solution containing 0.4 units Glycopeptidase F(Boehringer-Mannheim Biochemicals, Indianapolis, Ind.), 20 mM Tris-HCl(pH 7.5), 10 mM EDTA, and 1% Triton X-100 and subsequently maintainedfor 16 hours at 37 degrees C. The deglycosylated products were thenanalyzed by SDS-PAGE as previously described.

The results of the deglycosylation studies, shown in FIG. 7, lanes 4 and5, indicate that the 58 kDa form of huTF exhibits a higher relativemolecular than the 47 kDa form because of the presence of additionprotein moieties, i.e., the light chain.

The huTF thus isolated was relipidated to reconstitute its procoagulantactivity. The tissue factor:lipid ratio necessary to provide arelipidated tissue factor product having maximal activity wasempirically determined by dissolving the isolated huTF obtained above atvarious concentrations in HBS buffer solution (20 mM Hepes, pH 6.0, 140mM NaCl, 0.01% sodium azide) containing 0.1% BSA. The various huTFdilutions were then relipidated as described below, and that ratioproducing the highest recovered activity as determined in thecoagulation assay described in Example 2 was then prepared for lateruse.

Lipids for relipidation of huTF were prepared by extracting them fromrabbit brain acetone powder obtained from Sigma Chemical Co., St. Louis,Mo. The powder was admixed with heptane:butanol (2:1, v/v) at a ratio of25 ml heptane-butanol per gram of powder, and the solids containedtherein were recovered by filtration using a sintered glass funnel. Thisextraction process was repeated 6 times on the retained solids. Theretained solids were then dried by roto-evaporation, dissolved inchloroform and stored at minus 80 degrees C. As needed, portions of thechloroform-dissolved solids were dried under nitrogen and dissolved to aconcentration of 4 mg/ml in a solution of freshly prepared 0.25% sodiumdeoxycholate to form a rabbit brain phospholipids solution (RBPL).

For relipidation, 100 ul of each huTF dilution was admixed with 100 ulof RBPL solution, 0.76 ml of HBS solution containing 0.1% bovine serumalbumin (HBS/BSA) and 40 ul of a 100 mM cadmium chloride solution. Thisadmixture was maintained at 37 degrees C for 2 hours and the activity ofhuTF contained therein was determined in the coagulation assay describedin Example 2.

5. Production of Hybridomas and Monoclonal Antibodies

All hybridomas were produced using spleen cells from female Balb/c miceobtained from the Scripps Clinic and Research Institute vivarium rangingin age from 6 to 8 weeks.

a. Mouse TF8 Immunization

Five micrograms (ug) of affinity-isolated huTF prepared in Example 4 wasdissolved in normal saline at 100 ug/ml, combined and subsequentlyemulsified at a 1:1 ratio (V/V) with R-700 adjuvant obtained from RibiImmunochem Research, Inc., Hamilton, Mo. The emulsion was then injectedsubcutaneously (s.c.) into mouse TF8.

Mouse TF8 was similarly inoculated about two weeks later, using anemulsion containing denatured huTF and R-700 adjuvant. Denatured huTFwas prepared by boiling for 5 minutes TBS [150 mM CaCl, 50 mM Tris-HCl(pH 7.5)] containing 0.09% Triton X-100 0.93% SDS, 0.2M2-mercaptoethanol and huTF at 270 ug/ml. Thereafter the denatured huTFwas admixed with an equal volume of normal saline containing 0.6 mg/mlmouse serum albumin. Subsequently, 4 volumes of acetone were admixed tothe denatured huTF solution and the resulting admixture was maintainedovernight at minus 20 degrees C. The resulting precipitate was collectedby centrifugation at about 13,000 times g for 10 minutes, washed oncewith a 4:1 (V:V) acetone:H₂ O solution and then suspended in 200 ulnormal saline at a concentration of 0.1 mg/ml.

About four weeks after the initial injection, 33 ug of affinity isolated(non-denatured) huTF in 0.1 ml normal saline was admixed with 0.1 mls ofComplete Freund's Adjuvant (CFA) to form an emulsion. This emulsion wasthen injected intraperitoneally (i.p.) into mouse TF8.

About eight weeks after the initial inoculation, 15 ug of affinityisolated huTF in phosphate buffered saline (PBS) was injectedintravenously (i.v.) and an identical huTF/PBS inoculum was given i.v.twenty-four hours later. Mouse TF8's splenocytes were harvested forfusion three days later.

b. Mouse TF9 Immunization

Mouse TF9 was subjected to the same inoculation schedule as mouse TF8except that both Ribi adjuvant injections utilized huTF that had beendenatured prior to emulsification. In addition, the first PBS inoculumwas administered i.p. and 41/2 months after the CFA-containing inoculum.

c. Hybridoma Formation

The same fusion protocol was used for both TF8 and TF9 derivedsplenocytes. About 1×108 splenocytes from each mouse were admixed with2×10⁷ P3X63 Ag8.653.1 myeloma cells in 200 ul of a fusion mediumcomprising 30% w/v polyethylene glycol (PEG 4000, ATCC 25322-68-3).After cell fusion, the resulting hybridomas were seeded into 96 wellplates, cultured in HAT medium (hypoxanthine, aminopterin andthymidine), and subsequently screened for the ability to produceantibody molecule that reacts with huTF.

6. Screening Hybridomas for Production of Anti-huTF Antibody Molecules

One hundred ul of goat anti-mouse IgG (Boehringer-Mannheim Biochemicals,Indianapolis, Ind.) diluted to 20 ug/ml in TBS were admixed into thewells of Immulon 96-well flexible vinyl microtiter plates (DynatechLaboratories, Alexandria, Va.). The plates were then maintained for 1hour at 37 degrees C to allow the IgG to adsorb onto the walls of thewells. After washing three times with TBS, 100 ul of TBS/Tritoncontaining 3% ovalbumin was admixed into each well to block excessprotein binding sites.

a. Solid-Phase RIA

The wells were maintained for 1 hour at about 20 degrees C and then theblocking solution was removed by aspiration. Fifty ul of hybridomaculture supernate was admixed into each well. The resulting solid-liquidphase immunoreaction admixture was maintained at 37 degrees C for 1hour. The wells were then rinsed three times with TBS and excess liquidwas removed by aspiration.

Fifty ul of ¹²⁵ I-labeled huTF prepared in Example 4 and containingapproximately 1 ng of huTF and approximately 5×10⁵ cpm in TBS/Triton wasadmixed into each well to form a second solid-liquid phaseimmunoreaction admixture. The wells were maintained for 2 hours at 37degrees C and then rinsed three times with TBS/Triton to isolate thesolid-phase bound ¹²⁵ I-huTF-containing immunoreaction products. Excessliquid was removed by aspiration and the wells were allowed to dry.Individual wells were cut apart and the ¹²⁵ I contained in each well wasdetermined with a gamma counter.

Background radioactivity (no reaction of huTF with antibody) averagedabout 200-300 cpm per well, while positive reactions of huTF withantibody yielded 10000 cpm per well. Hybridomas assayed as positive forthe production of anti-huTF antibodies were selected and constitutehybridomas of the present invention. Subsequently, those hybridomas werescreened in the dot blot assay described below.

b. Dot Blot ELISA

Acetone precipitated huTF prepared in Example 4 was extracted twice witha 4:1 (V/V)-acetone:H₂ O solution. The precipitate that remained wasresuspended at 20 ug/ml of TBS. Twenty ng (1 ul) of this huTF solutionwas spotted onto BA83 nitrocellulose paper (Schleicher andSchuell,Keene, NH) next to a number written on the paper in indelibleink. The spotted huTF was air dried and individual spots were then cutout into paper circles using a punch. Individual paper circles wereimmersed into individual wells of a multi-well tray containing BLOTTO,[Johnson et al., Gene. Anal. Tech., 1:3 (1984)], and were maintained at37 degrees C for about 1 hour.

The BLOTTO was removed from the wells by aspiration and 200 ul ofhybridoma culture supernate was added to each well. The wells were thenmaintained at 37 degrees C for 2 hours. The paper circles were rinsedtwice with TBS, removed from the wells and combined into a single largercontainer for an additional rinse in TBS. Excess liquid was then removedfrom the container.

Alkaline phosphatase-conjugated anti-mouse IgG in the protoblot reagentkit (Promega Biotech, Ann Arbor, Mich.) was diluted 1:5700 in BLOTTO andcontacted with the paper circles. The Protoblot solution was maintainedin contact at 37 degrees C for 30 minutes. The paper circles were thenrinsed three times in TBS. Bound alkaline phosphatase was detected onthe paper circles using the chromogenic substrates supplied in theProtoblot kit according to the manufacturer's instructions.

Hybridomas assayed as positive for the production of anti-huTFantibodies capable of reacting with huTF in the dot blot assay as wellas the solid phase RIA described above were selected for furthercharacterization. Those hybridomas and the monoclonal antibodies theyproduce are shown in Table 5 in Example 13.

7. Isolation of Immunoglobulin IgG

Immunoglobulin IgG was isolated from the ascites fluid of a mousecontaining the mouse hybridoma cell line TF8-5G9 (ATCC number HB9382)using a Biorad Laboratories MAPS II system according to themanufacturer's instructions. The protein concentration of the isolatedIgG was determined using the BCA Protein Assay Reagent (Pierce ChemicalCo.) according to manufacturer's specifications.

8. Preparation of an Anti-huTF-Containing Solid Support forImmunoaffinity Isolation of huTF

Anti-huTF antibodies were activated for coupling to an agarose solidmatrix by dialyzing 10 mg of MAPS-isolated TF8-5G9 monoclonal antibody,prepared as described in Example 7, against 500 ml of a dialysis bufferconsisting of 0.1M MES, pH 6.5, for 16 hours at 4 degrees C with atleast one change of the dialysis buffer. The activated TF8-5G9antibodies were then admixed with 2 ml of AffiGel-10 agarose beads(Biorad) and the resulting coupling-reaction admixture was processedaccording to the manufacturer's instructions to form a TF8-5G9/agarosesolid support.

Excess protein binding sites on the solid support were then blocked,washed and vacuum filtered as described in Example 3 to formTF8-5G9/agarose cake.

9. Immunoaffinity Isolation of huTF

Brain-extract solution equivalent to about one-half of a human brain,i.e., about 100 mls, and prepared in Example 1 was dialyzed over threedays with two changes against a total of 6 liters of Buffer A at 4degrees C. The dialyzed brain-extract was then centrifuged at 10,000 x gfor 1.5 hours. The resulting supernatant was admixed with the glycineethyl ester-agarose cake prepared in Example 4 to form a solid-liquidphase reaction admixture. After being maintained for 2 hours at roomtemperature with rotation, the solid and liquid phases were separated byfiltration using a sintered glass funnel. The huTF-containing liquidphase was recovered and admixed with the TF8-5G9/agarose cake preparedin Example 8 to form a solid/liquid phase immunoreaction admixture.

The immunoreaction admixture was maintained overnight at 4 degrees Cwith rotation to allow formation of a tissue factor-containing solidphase immunoreaction product. The solid and liquid phases were thenseparated by filtration as previously described. The solid phase wasretained and then washed with 10 volumes of Buffer A. The solid phasewas then transferred to a glass chromatography column and washedsequentially with (1) 2 volumes of 1M NaCl containing 1% Triton X-100,and (2) 2 volumes of 0.1M glycine pH 4.0 containing 1% Triton X-100.

Any huTF immunologically bound to the solid support after the abovewashes was then released (eluted) by washing the solid support whileretained upon a sintered glass funnel with 20 mls of 0.1M glycine, pH2.5, and 1% Triton X-100. Eluted material was then collected, assayedfor huTF, pooled and dialyzed, all as described in Example 4.

The dialysate was subsequently admixed with four volumes of cold acetoneto precipitate the huTF protein. The precipitate was then collected bycentrifugation at 5,000 times g for 30 minutes at approximately -10degrees C. The resulting pellet was dried under nitrogen and a portionof the pellet was analyzed by SDS-polyacrylamide gel electrophoresis(SDS-PAGE) under denaturing conditions.

The results of that analysis, shown in FIG. 8, indicate that huTFh canbe immunoaffinity isolated with a yield of 33 mg of huTFh per gram ofdelipidated brain powder.

10. Inhibition of Coagulation by Anti-huTF Antibodies

Ten microliters of a hybridoma culture supernatant were admixed with 90ul of HBS/BSA containing about 2 ng of the relipidated huTF prepared inExample 4. The immunoreaction admixtures thus formed were maintained at37 degrees C for 30 minutes to allow the anti-huTF antibody molecules toimmunologically bind the huTF and form an immunoreaction product. Theimmunoreaction admixtures were subsequently assayed for huTFprocoagulant activity as described in Example 2. An irrelevant IgGpreparation was used in place of anti-huTF antibody as a negativecontrol.

An effective huTF concentration was extrapolated from the standard curveproduced as in Example 2 using the clotting time measured in thepresence of inhibitor. Inhibition was expressed as a percent ratio ofthe effective huTF concentration over the actual huTF concentrationused. Monoclonal antibody molecule preparations producing at least 50percent inhibition were selected as neutralizing antibody moleculecompositions of the present invention.

Numerous culture supernatants from hybridomas raised against isolatedhuTF as described in Example 5 were measured by the above procedure fortheir ability to inhibit initiation of coagulation. Those hybridomasfound to significantly inhibit initiation of coagulation are identifiedin Table 5.

Inhibition of coagulation by anti-huTF antibodies has also beenaccomplished using preformed huTF-factor VII complexes. Ten ulcontaining about 1 ng of relipidated huTF prepared in Example 4 wereadmixed with 70 ul of HBS/BSA, 10 ul 20 mM calcium chloride and, whereindicated, 10 ul containing about 25 ng of factor VII prepared asdescribed in Example 3. This admixture was maintained at 37 degrees Cfor 15 minutes to allow huTF to form a complex with any factor VIIavailable in the admixture. Thereafter 10 ul of solution was furtheradmixed containing about 10 ng of MAPS-isolated monoclonal antibodyprepared as described in Example 7, and this second admixture wasmaintained at 37 degrees C for 30 minutes. Inhibition of coagulation wasthen measured in the resulting admixture by adding first 100 ul of 20 mMcalcium chloride followed by 100 ul of either human citrated plasma orfactor VII depleted plasma prepared as described in Example 12 andobserving the clotting time in seconds. Percent inhibition was expressedas described in Example 10, and the results of these inhibitions withpreformed huTF-factor VII complex is shown in Table 6.

                  TABLE 6                                                         ______________________________________                                        Inhibition of huTF-Factor VII-Initiated                                       Coagulation by Anti-huTF Antibodies                                           Antibody    Factor VII.sup.d                                                                         Percent Inhibition                                     ______________________________________                                        I. Coagulation with Citrated Human Plasma                                     Blank.sup.a +          0                                                      TF85G9.sup.b                                                                              +           58%                                                   Control.sup.c                                                                             +          0                                                      TF85G9      -           83%                                                   Control     -          0                                                      II. Coagulation with Factor VII Depleted Human Plasma                         Blank       +          0                                                      TF85G9      +           58%                                                   Control     +          0                                                      ______________________________________                                         .sup.a "Blank" indicates that no monoclonal antibody was used in the          assay.                                                                        .sup.b "TF85G9" indicates that the monoclonal antibody isolated from          hybridoma TF8569 was the antibody used in the assay.                          .sup.c "Control" indicates that an irrelevant monoclonal antibody was the     antibody used in the assay.                                                   .sup.d "+" indicates that factor VII was added and allowed to form a          complex with purified huTF before antibody was added to the mixture.     

11. Polypeptide Synthesis

The polypeptides corresponding to the various huTFh regions utilizedherein were chemically synthesized on an Applied Biosystems Model 430APeptide Synthesizer using the symmetrical anhydride method ofHagenmaier, et al., Hoppe-Seyler's Z. Physiol. Chem., 353:1973 (1982).In addition to the polypeptides listed in Tables 1 and 2, thepolypeptides listed in Tables 3 below were also synthesized and comprisepolypeptides of the present invention useful for the production ofanti-polypeptide antibodies capable of reacting with huTFh.

                                      TABLE 3                                     __________________________________________________________________________    Antigenic Polypeptides                                                        __________________________________________________________________________    p121-155                                                                           H-TKVNVTVEDERTLVRRNNTFLSLRDVFGKDLIYTL-OH                                 p204-226                                                                           H-DSPVECMGQEKGEFREIFYIIGA-OH                                             p225-244                                                                           H-GAVVFVVIILVIILAISLHK-OH                                                p245-263                                                                           H-CRKAGVGQSWKENSPLNVS-OH                                                 __________________________________________________________________________

12. Inhibition of Coagulation by Polypeptides

The ability of the polypeptides of the present invention to inhibithuTF-initiated coagulation were assayed by first incubating thepolypeptides in the presence of factor VII/VIIa and calcium ions, andthen adding this mixture to factor VII/VIIa-deficient plasma andevaluating clotting times.

Human factor VII/VIIa was isolated as described in Example 3. Tenmicroliters of a solution of 200 ng of this isolated factor VII/VIIa perml of HBS/BSA was added to a solution comprising 100 ul of HBS, 20 ul of25 mM CaCl₂, and with 100 ul of TBS/Triton containing syntheticpolypeptide. Numerous admixtures were so prepared which containingvarying concentrations of the polypeptide and were then maintained at 37degrees C for 15 minutes. Relipidated tissue factor prepared asdescribed in Example 4 was diluted in HBS/BSA such that 10 ul wouldyield a coagulation time of approximately 45 seconds when tested in thecoagulation assay described in Example 2. The above maintained admixturewas further admixed with this 10 ul dilution of relipidated huTF, with100 ul of 25 mM CaCl₂, and with 100 ul of factor VII/VIIa-deficientplasma (George King Bio-Medical, Inc., Overland Park, Kans.) diluted 1part plasma to 1.5 parts HBS. The clotting time was then determined andplotted as described in Example 2. A prolongation of clotting time wastaken to indicate inhibition of coagulation by the syntheticpolypeptide. Percent inhibition was calculated as described in Example10. Polypeptides producing at least a 30% inhibition of coagulation wereconsidered huTFh binding site polypeptide analogs, i.e., polypeptidesp26-49, p146-167 and p161-189 as shown in section I of Table 4.

Alternatively, factor VII/VIIa-deficient plasma has been used in theabove inhibition assay prepared from plasma that was depleted of factorVII/VIIa by immunoaffinity adsorption with monoclonal antibodies. Amonoclonal antibody to human factor VII/VIIa was prepared essentially asdescribed in Example 5, except that factor VII/VIIa isolated asdescribed in Example 3 was used as immunogen in place of huTF. Theresulting hybridomas were evaluated by ELISA to identify a hybridomathat does not react with the human blood proteins Protein S, factor IX,factor X and factor II, available from Enzyme Research Laboratories,Inc., South Bend, Ind. Such a hybridoma FV11.F1.2H3-3.2, is availablefrom Dr. T. S. Edgington (Scripps Clinic and Research Foundation, LaJolla, Calif.). Immunoglobulin IgG was isolated from ascites of a mousecontaining hybridoma FV11 F1.2H3-3.2 and the isolated IgG was conjugatedto a solid support as described in Example 8. The resulting anti-factorVII/VIIa monoclonal antibody-containing solid support was used todeplete factor VII/VIIa from pooled, normal citrated plasma using theimmunoaffinity procedure described in Example 9 except that theliquid-phase containing plasma was collected and retained.

The ability of some of the polypeptides to competitively inhibitcoagulation when used in lipidated form was assessed in the above assayby substituting 100 ul of lipidated synthetic polypeptide in place ofthe 100 ul solution of synthetic polypeptide.

Lipidated synthetic peptides were prepared in the manner described inExample 4 for relipidation of isolated huTF except that syntheticpolypeptide was substituted for isolated huTF. The ratio 52 to 1 oflipid to polypeptide (w/w) was routinely utilized. Lipidatedpolypeptides producing at least 30% inhibition of coagulation wereconsidered huTFh binding site polypeptide analogs, when present inlipidated form, i.e., those polypeptides shown in section II of Table 4.

                  TABLE 4                                                         ______________________________________                                        Inhibition of huTF-Initiated Coagulation by                                   Polypeptide Analogues of huTFh                                                Peptide      Inhibition.sup.a                                                                        Concentration                                          ______________________________________                                        I. Non-Phospholipidated Peptides                                              p1-30        25.0      10 uM                                                  p26-49       88.8      10 uM                                                  p40-71       25.0      10 uM                                                  p40-49       25.0      10 uM                                                  p56-71       25.0      10 uM                                                  p72-104      25.0      10 uM                                                  p94-123      20.0      10 uM                                                  p121-155     10.0      10 uM                                                  p146-167     87.5      10 uM                                                  p161-189     32.5      10 uM                                                  p190-209     20.0      10 uM                                                  p204-226     20.0      10 uM                                                  None         0         --                                                     II. Phospholipidated Peptides                                                 p1-30        81.0      10 uM                                                  p26-40       83.0      10 uM                                                  p40-71       65.0      10 uM                                                  p50-71       73.3      30 uM                                                  p94-123      93.7      10 uM                                                  p121-155     55.0      10 uM                                                  p146-167     80.0      10 uM                                                  p161-189     94.0      10 uM                                                  ______________________________________                                         .sup.a Percent Inhibitions determined as described in Example 12.        

Exemplary dose-response curves obtained while performing the abovepolypeptide inhibition studies are shown in FIGS. 9 and 10.

13. Inhibition of Antibody-huTF Immunoreaction by Polypeptides

The wells of Immulon U-bottom 96-well plates made of flexible vinyl(Dynatech) were coated with goat anti-mouse IgG (Boehringer-Mannheim) asdescribed in Example 6 except that blocking of excess protein bindingsites was performed for 20 minutes at 37 degrees C.

Fifty ul of hybridoma culture supernatant were placed in each well andmaintained for 1 hour at 37 degrees C. The wells were then rinsed threetimes with TBS and excess liquid was removed by aspiration.

Isolated huTF was prepared on immunoaffinity columns as described inExample 9. The resulting acetone precipitates containing isolated huTFwere dissolved in TBS/Triton and the protein concentration wasdetermined using the BCA Protein Assay Reagent (Pierce) according tomanufacturer's specifications. Carbohydrate side groups on huTF werebiotinylated using biotin-hydrazide (ICN Biomedicals Inc., Plainview,N.Y.) according to the methods described by O'Shannessy et al., Immunol.Letters, 8:273-277 (1984) forming a biotinylated huTF solution.

Fifty ul of biotinylated huTF solution prepared to 60 ng/ml ofTBS/Triton was then placed in each well together with 5 uM syntheticpolypeptide and maintained for 1 hour at 37 degrees C. The wells werethen rinsed three times with TBS/Triton.

One hundred ul of streptavidin-conjugated alkaline phosphatase (DetekI-alk, Enzo Biochem Inc., New York, N.Y.) diluted 1/100 in TBScontaining 5 mM EDTA, 0.5% Triton X-100 and 1% BSA was placed into eachwell and maintained for 30 minutes at 37 degrees C. The wells were thenrinsed four times with a solution containing 10 mM potassium phosphate(pH 6.5), 2% BSA, 0.5% Triton X-100, 0.5M sodium chloride and 1 mM EDTA,followed by a single rinse with detection buffer [0.1M Tris-HCl (pH8.8), 0.1M NaCl, 5 mM MgCl₂ ].

One hundred ul of a solution containing 2 mM p-nitrophenyl phosphate indetection buffer was then added to each well and maintained for 1 hourat 37 degrees C. The optical absorbance at 405 nanometers (nm) was thenmeasured for each well using a Bio-Tek microplate reader (Bio-TekInstruments, Winooski, Vt.).

The results of the competitive inhibition study are shown in Table 5.

                                      TABLE 5                                     __________________________________________________________________________    Table of Peptide Interactions with Monoclonal Antibodies                      Mab.sup.a                                                                            p1-30                                                                             p26-49                                                                            p40-71                                                                            p41-49                                                                            p56-71                                                                            p72-104                                                                            p94-123                                                                            p121-155                                                                           p146-167                                                                           p161-189                                                                           p190-209                  __________________________________________________________________________    TF85G9 +                                                                      TF811D12                                                                             +                                                                      TF85C4                          +                                             TF821F2                +                                                      TF91D5                 +        +         +                                   TF92C4             +   +        +         +                                   TF92F6                     +                   +                              TF95C7             +   +        +         +                                   TF96B4                 +                  +                                   TF99C3             +   +        +         +                                   TF910C2                +                  +                                   TF91F1 +                                                                      TF91E7                     +              +         +                         TF91B8             +                      +    +                              TF91B9     +                                                                  TF94D11    +   +   +                                                          TF95G4     +       +                                                          TF95B7 +   +                                                                  TF96G4     +                                                                  TF97E10    +           +                                                      TF98E8 +   +           +                                                      TF99E1 +   +       +                                                          TF99B4     +   +                                                              TF96C8.sup.b                                                                         +   +   +                                                              TF910H5.sup.b                                                                            +           +                                                      TF99D6.sup.b                                                                             +           +                                                      TF910 H10.sup.b                                                                      +   +           +                                                      __________________________________________________________________________     .sup.a Each monoclonal antibody (Mab) was produced by a hybridoma having      the same designation. All monoclonal antibodies were screened using           hybridoma culture supernatants as described in Example 13.                    .sup.b These antibodies were considered nonneutralizing according to          results from Example 10.                                                 

Inhibition was considered significant if the measured absorbance valueobtained in the presence of polypeptide was more than one standarddeviation from the mean value obtained for a given antibody in theabsence of polypeptide.

14. Detection of huTF in a Body Sample by Two-Site ELISA

huTF can be detected in a body sample such as blood, plasma, saliva,urine, etc. by using two monoclonal antibodies that can concurrentlybind the same huTF molecule.

Immulon polystyrene U-bottom 96-well plates (Dynatech) are coated withgoat anti-mouse IgG (Boehringer-Mannheim) by first admixing into eachwell 100 ul of the IgG diluted to 10 ug/ml in TBS and then maintainingthe IgG solution in contact with the well overnight at 4 degrees C. Thewells are rinsed three times with TBS and 100 ul of TBS/Tritoncontaining 3% BSA is added to each well. The wells are then maintainedfor 1 hour at 37 degrees, rinsed three times with TBS and excess liquidis removed by aspiration.

One hundred ul of an anti-huTF antibody molecule-containing culturesupernatant from a first hybridoma, TF9-6B4, is admixed in each well andmaintained for 1 hour at 37 degrees C. The wells are then rinsed threetimes with TBS and excess liquid is removed by aspiration.

Immunoaffinity isolated and acetone precipitated huTF prepared as inExample 9 is dissolved in TBS/Triton. Dilutions of the huTF solution areprepared ranging from 5 ug/ml to 0.5 ng/ml of TBS/Triton and 100 ul of adilution is placed in a well of the Immulon plate. The dilutions of huTFare maintained in contact with the first antibody for 1 hour at 37degrees C The dilutions are then removed and the wells were rinsed threetimes with TBS/Triton. Excess liquid is removed by aspiration.

Anti-huTF antibodies are MAPS-isolated from ascites of a secondhybridoma, TF9-10H10, by the methods described in Example 7. Theantibody solution that results is measured for protein and subsequentlylabeled by biotinylation as described in Example 13.

The biotinylated anti-huTF antibody is diluted to 60 ng/ml of TBS/Tritonand 100 ul of this solution is admixed in each well. The wells aremaintained at 37 degrees C for 1 hour and then rinsed three times inTBS/Triton.

The bound biotinylated anti-huTF antibody is then detected using theDetek I-alk system described in Example 13. The monoclonal antibodiesused as a first and second antibody in this assay can be varied, so longas the two have the ability to bind concurrently to huTF. For example,where TF9-6B4 has been utilized as a first antibody, TF9-11D12 may beutilized as a second antibody in place of TF9-10H10. Thus, thisinvention contemplates any combination of antibodies which can bindconcurrently in this assay.

15. Construction of a DNA Segment Containing the Entire pre-huTFh CodingSequence

A DNA segment containing the entire pre-huTFh coding sequence can beconstructed in the following manner using recombinant plasmids pCTF64,pCTF403 and pCTF314, whose restriction maps are shown in FIG. 11, andprocedures that are well known in the art. See, for example, Maniatis etal., Molecular Cloning: A Laboratory Manual, Cold Spring HarborLaboratories, Cold Spring Harbor, N.Y. (1983).

The insert segments contained within the recombinant DNA plasmids shownin FIG. 11 have the EcoRI linker 5'-GGAATTCC-3' (Collaborative Research,Lexington, Mass.) at each terminus to facilitate the cloning process.These linker sequences are not present in the nucleotide sequence shownin FIG. 2 as they are not a part of the naturally occurring huTFh DNAcoding sequence. In order that the following descriptions ofconstruction of recombinant DNA molecules be clear in regard to thehuTFh DNA sequences involved, segments generated by digestions thatinclude EcoRI termini and thus may contain these additional linkersequences will be referred to by the nucleotide base number shown inFIG. 2. It is understood that the segments may contain these additionalsequences at their termini.

Plasmid pCTF64 is digested with the restriction endonucleases EcoRI andDraIII to produce a DNA segment including a nucleotide sequencecorresponding to the sequence shown in FIG. 2 from base residue 1 toresidue 296. The 302 nucleotide base pair (bp) segment so produced isisolated by size fractionation using an agarose gel and thendephosphorylated by treatment with alkaline phosphatase.

Plasmid pCTF403 is digested with the restriction endonuclease EcoRI toproduce a DNA segment including a nucleotide sequence corresponding tothe sequence shown in FIG. 2 from residue 776 to residue 1125. Theresulting 352 bp segment is isolated by size fractionation using anagarose gel.

Plasmid pCTF314 is digested with the restriction endonuclease EcoRI andthe resulting 647 bp segment is isolated by size fractionation. Thissegment includes a nucleotide sequence that corresponds to the sequenceshown in FIG. 2 from residue 135 to residue 775. The 647 bp segment isisolated by size fractionation and dephosphorylated with alkalinephosphatase.

The 352 bp segment and the dephosphorylated 647 bp segment are thenoperatively linked (ligated) by reaction with T4 DNA ligase thus forminga 999 bp segment having a nucleotide sequence corresponding to thesequence shown in FIG. 2 from residue 135 to residue 1125. The 999 bpsegment is then digested with the restriction endonuclease DraIIIcleaving the 999 bp segment at a position between base residues 296 and297 shown in FIG. 2, thereby generating a 168 bp segment and a 831 bpsegment. The dephosphorylated 302 bp segment and the 831 bp segment arethen operatively linked using T4 DNA ligase to form an 1125 bp segmentincluding a nucleotide sequence corresponding to the sequence shown inFIG. 2 from residue 1 to residue 1125.

The cloning plasmid vector pUC8 is linearized by digestion with EcoRI.The above prepared 1133 bp segment and the EcoRI digested vector areoperatively linked using T4 DNA ligase to form the circular recombinantDNA molecule pUC-pre-huTFh.

E. coli strain RR1 (Bethesda Research Laboratories, Gaithersburg, Md.)is transformed with pUC-pre-huTFh and successful transformants areselected on the basis of ampicillin resistance. The selectedtransformants are then cloned and screened for the presence of arecombinant DNA molecule having the pre-huTFh structural gene.

Screening for the presence of recombinant DNA molecules having thepre-huTFh structural gene is accomplished by digesting the rDNA fromeach selected transformant with EcoRI. The resulting EcoRI fragments areresolved into a pattern according to size on an agarose gel. RecombinantDNA molecules producing a three band pattern corresponding to DNAsegments of 352 bp, 781 bp and 2682 bp contain the pre-huTFh structuralgene. E. coli RR1 transformants having rDNA producing the abovedescribed EcoRI digestion pattern contain a recombinant DNA molecule ofthe present invention and are selected (recovered).

A DNA segment containing a substantial portion of the pre-huTFh codingsequence including the extracellular anchor region but lacking thetransmembrane anchor region at the carboxy terminus and thereby codingfor a soluble huTFh protein is constructed in the following manner.

Plasmid pCTF64 is digested with the restriction endonuclease EcoRI toproduce a DNA segment including a nucleotide sequence corresponding tothe sequence shown in FIG. 2 from residue 1 to residue 486. The 486nucleotide base pair (bp) segment so produced is isolated by sizefractionation using an agarose gel and then dephosphorylated bytreatment with alkaline phosphatase. The dephosphorylated 486 bp segmentis then digested with the restriction endonuclease DraIII cleaving the486 bp segment at a position between base residue 296 and 297 shown inFIG. 2, thereby generating a 296 bp segment and a 190 bp segment. The296 bp segment is isolated by size fractionation using an agarose gel.

Plasmid pCTF314 is digested with the restriction endonuclease EcoRI toproduce a DNA segment including a nucleotide sequence corresponding tothe sequence shown in FIG. 2 from residue 135 to residue 775. Theresulting 641 bp segment is isolated by size fractionation using anagarose gel and then dephosphorylated by treatment with alkalinephosphatase. The dephosphorylated 641 bp segment is then digested withDraIII cleaving the 641 bp segment at a position between base residue296 and 297 shown in FIG. 2, thereby generating a 162 bp segment and a479 bp segment. The 479 bp segment is isolated by size fractionationusing an agarose gel.

The above prepared segments of 296 bp and 479 bp are then operativelylinked (ligated) by reaction with T4 DNA ligase thus forming a 775 bpsegment having a nucleotide adapter sequence corresponding to thesequence shown in FIG. 2 from residue 1 to residue 775.

The cloning plasmid vector pUC18 is linearized by digestion with EcoRI.The above prepared 775 bp segment and the EcoRI digested vector areoperatively linked using T4 DNA ligase to form the circular recombinantDNA molecule pUC-pre-huTFh-T.

E. coli RR1 is transformed with pUC-pre-huTFh-T and ampicillin resistanttransformants, i.e., clones containing pUC-pre-huTFh-T, are selected.

Recombinant DNA molecule pUC-pre-huTFh-T is digested with EcoRI and theresulting 775 bp segment is isolated by size fractionation.

Synthetic oligonucleotide adapter segments having the sequences:

    5'-AATTTAGAGAATAAGAATTCGGG-3',

and

    3'-ATCTCTTATTCTTAAGCCC-5'

are produced according to the methods of Caruthers et al., J. Am. Chem.Soc., 103:3185 (1981), and Gait et al., Cold Spring Harbor Symp. Quant.Biol., 47:393 (1983) except that the oligonucleotides so prepared arenot phosphorylated with polynucleotide kinase so as to prevent operativelinkage (ligation) of these oligonucleotides to one another. Theoligonucleotides are annealed to form a double-stranded DNA linkersegment containing a cohesive EcoRI terminus and a blunt terminusaccording to the methods of Rotherstein et al., Methods in Enzymol.,68:98 (1979). This linker segment is then operatively linked to the 775bp segment obtained from pUC-pre-huTFh-T to form a 817 bp segmentcontaining one annealed segment at each end of the 775 bp segment. Theresulting 817 bp segment is then digested with EcoRI to convert eachtermini of the 817 bp segment from blunt to EcoRI cohesive, forming a805 bp segment. The resulting 805 bp segment is isolated by sizefractionation using an agarose gel.

The cloning plasmid vector pUC18 is linearized by digestion with EcoRI.The above prepared 805 bp segment and the EcoRI digested vector areoperatively linked using T4 DNA ligase to form the circular recombinantDNA molecule pUC-pre-huTFh-TR.

E. coli RR1 is transformed with pUC-pre-huTFh-TR and ampicillinresistant transformants, i.e., clones containing pUC-pre-huTFh-TR, areselected.

16. Production of huTFh by Expression of Recombinant huTFh CodingSequences

The expression of recombinant huTFh from recombinant DNA molecules maybe accomplished in a variety of expression media including procaryoticbacterial cells, non-vertebrate eucaryotic cells and higher (vertebrate)eucaryotic cells. Exemplary of such expression media are E. coli, S.cerevisiae and Chinese hamster ovary (CHO) cells, respectively.

a. Expression of pre-huTFh in E. coli

A recombinant DNA molecule capable of expressing the pre-huTFhstructural gene in E. coli cells can be constructed by isolating apre-huTFh gene-containing DNA segment from the pUC-pre-huTFh recombinantDNA molecule produced in Example 15 and operatively linking that segmentto a procaryotic expression vector.

Recombinant DNA molecule pUC-pre-huTFh is digested with EcoRI underconditions such that some but not all of the EcoRI sites present in theplasmid are cleaved. This partial digestion procedure is described inmore detail in Maniatis et al., Molecular Cloning: A Laboratory Manual,Cold Springs Harbor Laboratories, Cold Spring Harbor, N.Y. (1982). A1133 bp segment including a nucleotide sequence corresponding to thesequence shown in FIG. 2 from residue 1 to residue 1125 is isolated fromthe EcoRI partial digestion products by size fractionation.

The prokaryotic expression vector pKK223-3 (Pharmacia Fine Chemicals,Piscataway, N.J.) is linearized by digestion with EcoRI. The digestedvector and the 1133 bp pre-huTFh structural gene-containing segment areoperatively linked using T4 DNA ligase to form the circular recombinantDNA molecule pKK-pre-huTFh.

E. coli RR1 is transformed with pKK-pre-huTFh and ampicillin resistanttransformants, i.e., clones containing pKK-pre-huTFh, are selected.

b. Expression of huTFh in E. coli

A recombinant DNA molecule capable of expressing the huTF gene in E.coli is constructed by manipulating the 1133 bp segment prepared inExample 16a. That segment is first dephosphorylated with alkalinephosphatase and then digested with the restriction endonuclease BbvI.The resulting 964 bp segment includes a nucleotide sequencecorresponding to the sequence shown in FIG. 2 from residue 164 toresidue 1125 and is isolated by size fractionation.

Synthetic oligonucleotide adaptor segments having the sequences:

    5'-AATTGACATGTCAGGCACTACAAATACTGTGGCAGCATATAATT-3',

and

    3'-CTGTACAGTCCGTGATGTTTATGACACCGTCGTATATTAAATTG-5',

are produced as previously described and annealed to form adouble-stranded DNA linker segment containing cohesive EcoRI and BbvIends according to the methods of Rotherstein et al., Methods inEnzymol., 68:98 (1979). The linker is operatively linked first to the964 bp segment to form a 1008 bp segment. The 1008 bp segment is thenoperatively linked to the EcoRI digested vector pKK223-3, using T4 DNAligase to form the circular recombinant DNA molecule pKK-huTFh.

Recombinant DNA molecule pKK-huTFh differs from pKK-pre-huTFh only inthat (1) a segment from residue 1 to residue 129 is omitted, and (2) anew methionine codon is operatively linked before residue 130 such thatprotein expression (translation) begins at the inserted methioninecodon.

The recombinant DNA molecules pKK-pre-huTFh and pKK-huTFh are introducedinto a prokaryotic host medium compatible with expression of the huTFhor pre-huTFh protein encoded by the structural gene contained within.Exemplary of host cells containing such medium are E. coli strain RR1.The host is transformed with the recombinant DNA molecule, culturedunder conditions compatible with cell growth and expression of therecombinant DNA and the expressed protein is harvested by well knowntechniques.

c. Expression of pre-huTFh in CHO Cells

A recombinant DNA molecule capable of expressing the pre-huTFh gene invertebrate cells is constructed using the 1133 bp segment prepared inExample 16a.

Synthetic oligonucleotide adapter segments having the sequences:

    5'-AATTCCCGGG-3',

and

    5'-GATCCCCGGG-3',

are produced using the methods of Caruthers et al., supra and Gait etal., supra. The oligonucleotide adapter segments are then linked to eachterminus of the 1133 bp segment using the methods described byRotherstein et al., Methods in Enzymol., 68:98 (1979). The EcoRIcohesive termini originally present on the 1133 bp segment are therebyconverted to BglII cohesive termini.

The eucaryotic simian virus (SV40) based expression vector, pKSV-10(Pharmacia Fine Chemicals, Piscataway, N.J.), is linearized by digestionwith the restriction endonuclease BolII. The BglII-adapted 1133 bpsegment and the BglII-digested vector are operatively linked using T4DNA ligase to form the circular recombinant DNA molecule pSV-pre-huTFh.

E. coli RR1 is transformed with pSV-pre-huTFh and successfultransformants are selected on the basis of ampicillin resistance andcloned. The selected transformants are then cloned and screened for thepresence of pSV-pre-huTFh by assaying each clone for the presence ofexpressed pre-huTFh protein using monoclonal antibody TF8-5G9.

d. Expression of huTFh in CHO Cells

Recombinant DNA molecule capable of expressing the huTFh gene inmammalian cells is constructed by digesting pSV-pre-huTFh from Example16c with the restriction endonuclease BglII. The resulting 1153 bpsegment is isolated by size fractionation and subsequently digested withthe restriction endonuclease BbvI. The resulting 974 bp segment includesa nucleotide adapter sequence corresponding to the sequence shown inFIG. 2 from residue 164 to residue 1125 and is isolated by sizefractionation.

Synthetic oligonucleotide adapter segments having the sequences:

    5'-GATCGACATGTCAGGCACTACAAATACTGTGGCAGCATATAATT-3',

and

    3'-CTGTACAGTCCGTGATGTTTATGACACCGTCGTATATTAAATTG-5',

are produced as previously described and annealed to form adouble-stranded DNA linker segment containing cohesive BglII and BbvIcohesive termini. The linker is then operatively linked to the 974 bpsegment using T4 DNA ligase to form a 1018 bp segment including anucleotide sequence corresponding to the sequence shown in FIG. 2 fromresidue 130 to residue 1125.

The plasmid expression vector pKSV-10 is linearized by digestion withBglII and then operatively linked to the 1018 bp segment using T4 DNAligase to form the circular recombinant DNA molecule pSV-huTFh.

The recombinant DNA molecules pSV-pre-huTFh and pSV-huTFh are introducedinto a eucaryotic host medium compatible with expression of the huTFh orpre-huTFh protein encoded by the structural gene contained within.Exemplary of host cells containing such a medium are CHO cells.

The host is transfected with the recombinant DNA molecule and stabletransformants are selected by well known techniques. See for exampleGraham et al., Virol., 52:456 (1973); and Southern et al., J. Mol. Appl.Genet., 1:327-341 (1982). Transformed host cells are cultured underconditions compatible with cell growth and expression of the recombinantDNA and the expressed protein is harvested by well known techniques.

e. Expression of pre-huTFh in Yeast

A recombinant DNA molecule capable of expressing the pre-huTFh gene inS. cerevisiae is constructed by preparing oligonucleotide adaptersegments having the sequence:

    5'-AATTCCCGGG-3',

and

    5'-CGCCCGGG-3',

and linking them to the termini of the 1133 bp segment of Example 16a aspreviously described. The adapted segment thus formed has ClaI cohesivetermini.

The yeast expression vector, pTDTI (American Type Tissue Collection#ATCC 31255) is linearized by digestion with the restrictionendonuclease ClaI. The above ClaI-adapted 1133 bp segment and the ClaIdigested vector are operatively linked using T4 DNA ligase to form thecircular recombinant DNA molecule pY-pre-huTFh.

E. coli RR1 is transformed with pre-huTFh and transformants expressingthe pre-huTFh structural gene are identified and selected as describedin Example 16c.

f. Expression of huTFh in Yeast

A recombinant DNA molecule capable of expressing the huTFh structuralgene in S. cerevisiae is constructed by digesting pY-pre-huTFh with ClaIto produce a 1151 bp segment including a nucleotide sequencecorresponding to the sequence shown in FIG. 2 from residue 1 to residue1125. After isolation by size fractionation, the 1151 bp segment isdigested with the BbvI to produce a 978 bp segment including anucleotide sequence corresponding to the sequence shown in FIG. 2 fromresidue 164 to residue 1125. The 978 bp segment is then isolated by sizefractionation.

Synthetic oligonucleotide adapter segments having the sequences:

    5'-CGGACATGTCAGGCACTACAAATACTGTGGCAGCATATAATT-3',

and

    3'-CTGTACAGTCCGTGATGTTTATGACACCGTCGTATATTAAATTG-5',

are produced and annealed as previously described to form DNA adaptersegments having ClaI and BbvI cohesive termini. The adapter segment isfirst operatively linked to the 978 bp segment to form a 1020 bpsegment. The 1020 bp segment is subsequently linked to the ClaI-digestedpTDTl vector, prepared as described in 16e., using T4 DNA ligase to formthe circular recombinant DNA molecule pY-huTFh.

The recombinant DNA molecules pY-pre-huTFh and pY-huTFh are introducedinto a yeast host medium compatible with expression of the huTFh orpre-huTFh protein encoded by the structural gene contained within.Exemplary of host cells containing such a medium are S. cerevisiaecells.

The host is transformed with the recombinant DNA molecule and cultivatedin selection medium to isolate successfully transformed cells by wellknown techniques. See, for example, Hinnen et al., Proc. Natl. Acad.Sci. U.S.A., 75:1929 (1978); and Miyajima et al., Mol. Cell. Biol.,4:407 (1984). Transformed cells are cultured under conditions compatiblewith cell growth and expression of the recombinant DNA, and theexpressed protein is harvested by well known techniques.

g. Production of Soluble huTFh by Expression of Recombinant huTFh CodingSequences

The expression of soluble huTFh from recombinant DNA molecules may beaccomplished in a variety of expression media in a manner similar tothat described in Example 16 for pre-huTFh and huTFh. In that example a1133 bp pre-huTFh structural gene containing segment having EcoRIcohesive ends is produced in Example 16a and subsequently manipulated inExamples 16b-f resulting in vectors capable of expressing eitherpre-huTFh or huTFh in three exemplary expression mediums, E. coli, S.cerevisiae, and CHO cells. Similarly the 805 bp segment containing asoluble pre-huTFh structural gene having EcoRI cohesive ends andprepared in Example 16a is manipulated according to the methodsdescribed in Examples 16b-f to produce expression vectors capable ofexpressing a soluble form of either pre-huTFh or huTFh (i.e.,pre-huTFh-TR or huTFh-TR) in those same expression media.

17. Inhibition of Coagulation by Polypeptides p24-35 and p152-169

Polypeptides p24-35 and p152-169, whose amino acid residue sequences areshown in Table 7, were synthesized as described in Example 11.

                  TABLE 7                                                         ______________________________________                                        Designation.sup.a                                                                          Amino Acid Residue Sequence                                      ______________________________________                                        p24-35       H-EWEPKPVNQVYT-OH                                                p152-169     H-IYTLYYWKSSSSGKKTAK-OH                                          ______________________________________                                         .sup.a The laboratory designation of each polypeptide represents the          included amino acid residue sequence as shown in FIG. 1.                 

Polypeptides p24-35 and p152-169 were then assayed for their ability tocompetitively inhibit huTF-initiated coagulation as described in Example12. The results of this study are shown in FIG. 12 and indicate thatp24-35 and p152-169 are capable of inhibiting 45% and 25%, respectively,of the huTF-initiated coagulation when utilized at 10 uM concentrations.It should be noted that in this study background inhibitions such as forthose peptides indicated by a closed circle in FIG. 12 were lower thanthe study shown in Table 4. As a result, polypeptides producing at leasta 20% inhibition of coagulation at a concentration of 10 uM in thisstudy were considered huTF binding site polypeptide analogs.

Thus, polypeptides p24-35 and p152-169 represent huTFh polypeptidebinding-site analogs of the present invention. It should also be notedthat the results obtained with p24-35, when taken in view of the similarresults obtained with polypeptide p25-49, indicate that a huTFh-factorVII/VIIa binding site can be formed by the amino acid residue sequencethose two polypeptides have in common, i.e., residues 30-35 as shown inFIG. 1 (-VNQVYT-).

18. Kinetics of Inhibition of Coagulation by Anti-huTF Antibodies

To determine the time in which anti-huTF antibodies were capable ofinhibiting huTF-initiated coagulation, the time-course of inhibition wasmeasured using the inhibition assay described in Example 10.

Approximately 1 ng of MAPS-isolated TF8-5G9 monoclonal antibody preparedas described in Example 7 was admixed in 100 ul of HBS/BS withapproximately 1 ng of relipidated huTF prepared as described in Example4. The various admixtures so formed were maintained at 37 degrees C forvarying times from about 1 to about 60 minutes to allow the anti-huTFantibody molecule to immunologically bind the huTF and form animmunoreaction product. At the times specified in FIG. 13 each admixturewas subsequently assayed for huTF procoagulant activity as described inExample 2 and the percent inhibition was then expressed as described inExample 10.

FIG. 13 shows the results of such a kinetic measurement which indicatesthat inhibitions of huTF-initiated coagulation greater than 65 percentoccurred in less than 10 minutes at the concentration of antibody andpurified huTF utilized in this assay. It is believed that more rapid andcomplete inhibitions would result from higher concentrations ofanti-huTF antibody.

19. Dose-Response of Inhibition of huTF-Initiated Coagulation byAnti-huTF Antibodies

The ability of the anti-huTF antibodies of the present invention toinhibit huTF-initiated coagulation over a range of antibody dosages wasassayed by the methods described in Example 10 with the followingmodifications. One ng of relipidated huTF prepared in Example 4 wasadmixed in 0.1 ml of HBS/BSA with various amounts of TF8-5G9 monoclonalantibody isolated as described in Example 7. The admixtures thusprepared were maintained to form immunoreaction products and weresubsequently assayed for huTF procoagulant activity as described inExample 10.

Results of such a dose-response assay are shown in FIG. 14 and indicatethat inhibitions are half of maximum at approximately 1 to 5 ng ofanti-huTF per ml for the concentration of huTF used in this study.

A similar dose-response was performed using lysed human cells as thesource of huTF.

Human fibroblast cell line GM1381 (NIGMS Human Genetic Mutant CellRepository) was cultured in Dulbecco's Modified Eagle's Medium (DMEM,Gibco Laboratories, Grand Island, N.Y.) supplemented with 2 mMglutamine, 5% fetal calf serum and antibiotics at 37 degrees C and under7% (v/v) carbon dioxide in air. GM1381 cells were grown and harvested,and a pellet of 30×10⁶ cells was prepared by centrifugation and frozenat minus 70 degrees C. This frozen pellet was quick thawed by theaddition of 9 mls of 15 mM betaoctylglucopyranoside (Sigma) in HN buffer(25 mM Hepes, 140 mM NaCl, pH 7.0) and maintained at 37 degrees C for 10minutes to lyse the cells after which time 18 mls of HN was admixed toform a cell lysate.

Monoclonal antibody TF8-5G9 isolated as described in Example 7 wasdiluted with 0.01% BSA (Sigma, RIA grade) to the various dosagesspecified in FIG. 15. Twenty-five ul of each antibody dilution was thenadmixed with 225 ul of the above prepared cell lysate and maintained at37 degrees C for 60 minutes to allow the antibody to immunoreact withany huTF present in the cell lysate and form an immunoreaction product.Thereafter 50 ul of a 25 mM CaCl₂ solution was admixed with 50 ul of thesolution containing the immunoreaction product followed by 50 ul ofcitrated human plasma to initiate coagulation. The admixtures thusformed were maintained at 37 degrees and the time between the additionof the plasma and the formation of a clot was measured. The effectivehuTF concentration and percent inhibition was calculated as described inExample 10.

Results from a dose-response inhibition assay using human GM1381 celllysates as a source of huTF are shown in FIG. 15. Those results indicatethat TF8-5G9 anti-huTF antibody produces half maximal inhibition of thiscell lysate source of huTF at approximately 8-10 ng antibody per ml.

The foregoing specification, including the specific embodiments andexamples, is intended to be illustrative of the present invention and isnot to be taken as limiting. Numerous other variations and modificationscan be effected without departing from the true spirit and scope of thepresent invention.

What is claimed is:
 1. An isolated DNA segment comprising no more thanabout 1133 nucleotide base pairs and including a nucleotide sequencecoding for a human tissue factor heavy chain protein having an aminoacid residue sequence represented by FIG. 1 from about residue 1 toabout residue
 263. 2. The DNA segment of claim 1 wherein said nucleotidesequence is represented by FIG. 2 from about base 130 to about base 918.3. A recombinant DNA molecule comprising a vector operatively linked toa DNA segment coding for a human tissue factor heavy chain protein. 4.The recombinant DNA molecule of claim 3 wherein said DNA segment codesfor a protein having an amino acid residue sequence represented by FIG.1 from about residue 1 to about residue
 263. 5. The recombinant DNAmolecule of claim 3 wherein said DNA segment has a nucleotide basesequence represented by FIG. 2 from about base 130 to about base
 918. 6.A method of preparing a mature human tissue factor heavy chain (huTFh)protein comprising the steps of:a) initiating a culture, in a nutrientmedium, of mammalian cells transformed with a recombinant DNA moleculecomprising an expression vector operatively linked to a first DNAsegment coding for said mature huTFh and a second DNA segmentoperatively linked to said first DNA segment and coding for an aminoacid residue leader sequence, so that said recombinant DNA moleculecodes for a huTFh precursor; b) maintaining said culture for a timeperiod sufficient for said transformed cells to express said maturehuTFh protein; and c) recovering said mature huTFh protein from saidculture.
 7. The method according to claim 6 wherein said recombinant DNAmolecule has a nucleotide base sequence represented by FIG. 2 from base34 to base 786.